diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d448479c8fdc8dcec868c.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d448479c8fdc8dcec868c.md
index e84e64dbfe2..55bbecdfc49 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d448479c8fdc8dcec868c.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d448479c8fdc8dcec868c.md
@@ -7,7 +7,7 @@ dashedName: step-81
 
 # --description--
 
-Declare a `functionCall` variable, and assign it this regular expression: `/([a-z]*)\(([0-9., ]*)\)(?!.*\()/i`
+Declare a `functionCall` variable, and assign it this regular expression: `/([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i`
 
 This expression will look for function calls like `sum(1, 4)`.
 
@@ -28,7 +28,9 @@ assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*cons
 You should assign `functionCall` the provided regular expression.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i/);
+
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*\,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i/);
+
 ```
 
 # --seed--
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d44da986f2bc9b72f5fe2.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d44da986f2bc9b72f5fe2.md
index 76b05cfc73d..1acd44c545d 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d44da986f2bc9b72f5fe2.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d44da986f2bc9b72f5fe2.md
@@ -14,55 +14,55 @@ Declare a `toNumberList` function which takes an `args` parameter, and returns t
 You should declare a `toNumberList` variable.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*(?:const|let|var)\s+toNumberList\s*=/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*(?:const|let|var)\s+toNumberList\s*=/);
 ```
 
 You should use `const` to declare your `toNumberList` variable.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=/);
 ```
 
 Your `toNumberList` variable should be an arrow function.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*(\(\s*(?:args)?\s*\)|args)\s*=>/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*(\(\s*(?:args)?\s*\)|args)\s*=>/);
 ```
 
 Your `toNumberList` function should have an `args` parameter.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*(\(\s*args\s*\)|args)\s*=>/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*(\(\s*args\s*\)|args)\s*=>/);
 ```
 
 Your `toNumberList` function should use an implicit return.
 
 ```js
-assert.notMatch(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*(\(\s*args\s*\)|args)\s*=>\s*\{/);
+assert.notMatch(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*(\(\s*args\s*\)|args)\s*=>\s*\{/);
 ```
 
 Your `toNumberList` function should return the result of calling the `.split()` method of `args`.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*(\(\s*args\s*\)|args)\s*=>\s*args\.split\(/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*(\(\s*args\s*\)|args)\s*=>\s*args\.split\(/);
 ```
 
 You should split `args` on the `,` character.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*(?:\(\s*args\s*\)|args)\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*(?:\(\s*args\s*\)|args)\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)/);
 ```
 
 You should chain the `.map()` method to the `.split()` method.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*(?:\(\s*args\s*\)|args)\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*(?:\(\s*args\s*\)|args)\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(/);
 ```
 
 You should pass a reference to `parseFloat` as the callback to `.map()`.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*(?:\(\s*args\s*\)|args)\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*(?:\(\s*args\s*\)|args)\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?/);
 ```
 
 
@@ -143,7 +143,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
 
 }
 --fcc-editable-region--
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d451c2e44afca71b67818.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d451c2e44afca71b67818.md
index c9e0af0169c..369231720a9 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d451c2e44afca71b67818.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d451c2e44afca71b67818.md
@@ -14,37 +14,37 @@ Declare an `apply` function that takes a `fn` and `args` parameter.
 You should declare an `apply` variable.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*(?:var|let|const)\s+apply\s*=/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*(?:var|let|const)\s+apply\s*=/);
 ```
 
 You should use `const` to declare your `apply` variable.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=/);
 ```
 
 Your `apply` variable should be assigned an arrow function.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(/);
 ```
 
 Your `apply` function should have `fn` as its first parameter.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn/);
 ```
 
 Your `apply` function should have `args` as its second parameter.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)/);
 ```
 
 Your `apply` function should be empty.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*\{\s*\}/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*\{\s*\}/);
 ```
 
 # --seed--
@@ -124,7 +124,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
 
 }
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4554721d43cb19a68bc4.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4554721d43cb19a68bc4.md
index 850121a0317..aec59ba845b 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4554721d43cb19a68bc4.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4554721d43cb19a68bc4.md
@@ -16,25 +16,25 @@ Remember that `fn` might not be lowercase, so you'll need to convert it to a low
 Your `apply` function should use an implicit return.
 
 ```js
-assert.notMatch(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*\{/);
+assert.notMatch(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*\{/);
 ```
 
 Your `apply` function should access the `spreadsheetFunctions` object.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions/);
 ```
 
 Your `apply` function should access the property of the `spreadsheetFunctions` object that matches the `fn` value.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn/);
 ```
 
 Your `apply` function should call the `.toLowerCase()` method on `fn` in the property access.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]/);
 ```
 
 
@@ -116,7 +116,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => {}
 }
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d45b739da5ecbf830c108.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d45b739da5ecbf830c108.md
index f5757ba19eb..3a0de4a049e 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d45b739da5ecbf830c108.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d45b739da5ecbf830c108.md
@@ -14,19 +14,19 @@ Your `apply` function is returning the spreadsheet function, but not actually ap
 Your `apply` function should call the `spreadsheetFunctions[fn.toLowerCase()]` function.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(/);
 ```
 
 You should pass a `toNumberList()` call to your `spreadsheetFunctions[fn.toLowerCase()]` call.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(/);
 ```
 
 You should pass `args` to your `toNumberList()` call.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)/);
 ```
 
 # --seed--
@@ -106,7 +106,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()];
 }
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d45ee725632cca2555146.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d45ee725632cca2555146.md
index 83dcd338a09..60b2dcb1650 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d45ee725632cca2555146.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d45ee725632cca2555146.md
@@ -14,19 +14,19 @@ Now your `applyFunction` needs to return a result. Return the result of calling
 Your `applyFunction` function should return the result of calling the `.replace()` method on `str2`.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(/);
 ```
 
 You should pass `functionCall` as the first argument to your `.replace()` call.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall/);
 ```
 
 You should pass an empty arrow function as the second argument to your `.replace()` call.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*\)\s*=>\s*\{\s*\}/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*\)\s*=>\s*\{\s*\}/);
 ```
 
 
@@ -107,7 +107,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
 
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4626420eeecd51f241c2.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4626420eeecd51f241c2.md
index cbfdbf6be78..82049959f09 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4626420eeecd51f241c2.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4626420eeecd51f241c2.md
@@ -16,43 +16,43 @@ Remember to make `fn` lower case.
 Your callback function should have `match` as the first parameter.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match/);
 ```
 
 Your callback function should have `fn` as the second parameter.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn/);
 ```
 
 Your callback function should have `args` as the third parameter.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>/);
 ```
 
 Your callback function should use an implicit return.
 
 ```js
-assert.notMatch(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*\{/);
+assert.notMatch(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*\{/);
 ```
 
 Your callback function should return the result of calling the `.hasOwnProperty()` method on the `spreadsheetFunctions` object.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\.hasOwnProperty\(/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\.hasOwnProperty\(/);
 ```
 
 You should pass `fn` to the .`hasOwnProperty()` method.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\.hasOwnProperty\(\s*fn/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\.hasOwnProperty\(\s*fn/);
 ```
 
 You should call the `.toLowerCase()` method on `fn`.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\.hasOwnProperty\(\s*fn\.toLowerCase\(\s*\)\s*\)/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\.hasOwnProperty\(\s*fn\.toLowerCase\(\s*\)\s*\)/);
 ```
 
 # --seed--
@@ -132,7 +132,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, () => {})
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d467c6994f4ce0dc416a4.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d467c6994f4ce0dc416a4.md
index 1049cf16158..d8592b22b6f 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d467c6994f4ce0dc416a4.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d467c6994f4ce0dc416a4.md
@@ -14,31 +14,31 @@ Use the ternary operator to turn your `.hasOwnProperty()` call into the conditio
 Your callback function should use ternary syntax.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\.hasOwnProperty\(\s*fn\.toLowerCase\(\s*\)\s*\)\s*\?/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\.hasOwnProperty\(\s*fn\.toLowerCase\(\s*\)\s*\)\s*\?/);
 ```
 
 If the ternary condition is true, your callback function should return the result of calling `apply()`.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\s*\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\s*\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\.hasOwnProperty\(\s*fn\.toLowerCase\(\s*\)\s*\)\s*\?\s*apply\(/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\s*\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\s*\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\.hasOwnProperty\(\s*fn\.toLowerCase\(\s*\)\s*\)\s*\?\s*apply\(/);
 ```
 
 You should pass `fn` as the first argument to your `apply()` call.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\.hasOwnProperty\(\s*fn\.toLowerCase\(\s*\)\s*\)\s*\?\s*apply\(\s*fn/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\.hasOwnProperty\(\s*fn\.toLowerCase\(\s*\)\s*\)\s*\?\s*apply\(\s*fn/);
 ```
 
 You should pass `args` as the second argument to your `apply()` call.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\.hasOwnProperty\(\s*fn\.toLowerCase\(\s*\)\s*\)\s*\?\s*apply\(\s*fn\s*,\s*args\s*\)/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\.hasOwnProperty\(\s*fn\.toLowerCase\(\s*\)\s*\)\s*\?\s*apply\(\s*fn\s*,\s*args\s*\)/);
 ```
 
 If the ternary is false, you should return `match`.
 
 ```js
-assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\.hasOwnProperty\(\s*fn\.toLowerCase\(\s*\)\s*\)\s*\?\s*apply\(\s*fn\s*,\s*args\s*\)\s*:\s*match/);
+assert.match(code, /const\s+applyFunction\s*=\s*\(?\s*str\s*\)?\s*=>\s*\{\s*const\s+noHigh\s*=\s*highPrecedence\(\s*str\s*\);?\s*const\s+infix\s*=\s*\/\(\[(?:\\d\.|\.\\d)\]\+\)\(\[(?:\+-|-\+)\]\)\(\[(?:\\d\.|\.\\d)\]\+\)\/;?\s*const\s+str2\s*=\s*infixEval\(\s*noHigh\s*,\s*infix\s*\);?\s*const\s+functionCall\s*=\s*\/\(\[a-z0-9\]\*\)\\\(\(\[0-9\., \]\*\)\\\)\(\?!\.\*\\\(\)\/i;?\s*const\s+toNumberList\s*=\s*\(?\s*args\s*\)?\s*=>\s*args\.split\(\s*('|"|`),\1\s*\)\.map\(\s*parseFloat\s*\);?\s*const\s+apply\s*=\s*\(\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\s*\[\s*fn\.toLowerCase\(\s*\)\s*\]\s*\(\s*toNumberList\(\s*args\s*\)\s*\);?\s*return\s+str2\.replace\(\s*functionCall\s*,\s*\(\s*match\s*,\s*fn\s*,\s*args\s*\)\s*=>\s*spreadsheetFunctions\.hasOwnProperty\(\s*fn\.toLowerCase\(\s*\)\s*\)\s*\?\s*apply\(\s*fn\s*,\s*args\s*\)\s*:\s*match/);
 ```
 
 # --seed--
@@ -118,7 +118,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) );
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d46c03e7d02cecb30f021.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d46c03e7d02cecb30f021.md
index 222c5c8a20d..e4814974413 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d46c03e7d02cecb30f021.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d46c03e7d02cecb30f021.md
@@ -111,7 +111,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? apply(fn, args) : match);
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4717a689e1cfa232e357.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4717a689e1cfa232e357.md
index 48b1cab80ed..11baf72909b 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4717a689e1cfa232e357.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4717a689e1cfa232e357.md
@@ -131,7 +131,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? apply(fn, args) : match);
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4769ba65f1d05ef6b634.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4769ba65f1d05ef6b634.md
index c1249111d86..e2e4950db95 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4769ba65f1d05ef6b634.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4769ba65f1d05ef6b634.md
@@ -107,7 +107,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? apply(fn, args) : match);
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d47c8f58107d10f1e5106.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d47c8f58107d10f1e5106.md
index 9ef5920b36a..347ff88c936 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d47c8f58107d10f1e5106.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d47c8f58107d10f1e5106.md
@@ -105,7 +105,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? apply(fn, args) : match);
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4813c17b37d1e261a566.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4813c17b37d1e261a566.md
index c2b4d2b8c71..fe874cf5f67 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4813c17b37d1e261a566.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4813c17b37d1e261a566.md
@@ -105,7 +105,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? apply(fn, args) : match);
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d486aec20f7d2a581cc36.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d486aec20f7d2a581cc36.md
index ac6184b9d56..1f6781a5a5d 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d486aec20f7d2a581cc36.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d486aec20f7d2a581cc36.md
@@ -93,7 +93,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? apply(fn, args) : match);
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d48b936802fd34c3f05af.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d48b936802fd34c3f05af.md
index 98ffeb00088..a2282da503c 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d48b936802fd34c3f05af.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d48b936802fd34c3f05af.md
@@ -134,7 +134,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? apply(fn, args) : match);
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d498c8ebc31d3f753b22e.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d498c8ebc31d3f753b22e.md
index a4c682f9df4..cc8b97da8c6 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d498c8ebc31d3f753b22e.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d498c8ebc31d3f753b22e.md
@@ -127,7 +127,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? apply(fn, args) : match);
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d49bfff9079d4b38df115.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d49bfff9079d4b38df115.md
index 43c6ebe6441..0a62d2e9cc6 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d49bfff9079d4b38df115.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d49bfff9079d4b38df115.md
@@ -135,7 +135,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? apply(fn, args) : match);
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4a07a8fb14d55cd70e09.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4a07a8fb14d55cd70e09.md
index 0e9787dff11..5efd22ab0b7 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4a07a8fb14d55cd70e09.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4a07a8fb14d55cd70e09.md
@@ -128,7 +128,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? apply(fn, args) : match);
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4a5b32a1cad6165df286.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4a5b32a1cad6165df286.md
index 983d30989b0..8e04fbe9fc2 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4a5b32a1cad6165df286.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4a5b32a1cad6165df286.md
@@ -123,7 +123,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? apply(fn, args) : match);
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4a8dbc04c6d6bb0001f8.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4a8dbc04c6d6bb0001f8.md
index 34ae3e371aa..93ee83dcf49 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4a8dbc04c6d6bb0001f8.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4a8dbc04c6d6bb0001f8.md
@@ -116,7 +116,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? apply(fn, args) : match);
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4ab9b3b4c5d74fdd2154.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4ab9b3b4c5d74fdd2154.md
index b221e737fdb..c380ecd405a 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4ab9b3b4c5d74fdd2154.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4ab9b3b4c5d74fdd2154.md
@@ -120,7 +120,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? apply(fn, args) : match);
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4b3d80ea98d824c8a4f9.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4b3d80ea98d824c8a4f9.md
index 340f98877da..65eef33f6de 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4b3d80ea98d824c8a4f9.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/646d4b3d80ea98d824c8a4f9.md
@@ -120,7 +120,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? apply(fn, args) : match);
@@ -259,7 +259,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? apply(fn, args) : match);
diff --git a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/6491d38f5b09a021c4b5d5fe.md b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/6491d38f5b09a021c4b5d5fe.md
index eb5424ffa9d..41696356307 100644
--- a/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/6491d38f5b09a021c4b5d5fe.md
+++ b/curriculum/challenges/english/15-javascript-algorithms-and-data-structures-22/learn-functional-programming-by-building-a-spreadsheet/6491d38f5b09a021c4b5d5fe.md
@@ -129,7 +129,7 @@ const applyFunction = str => {
   const noHigh = highPrecedence(str);
   const infix = /([\d.]+)([+-])([\d.]+)/;
   const str2 = infixEval(noHigh, infix);
-  const functionCall = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
+  const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
   const toNumberList = args => args.split(",").map(parseFloat);
   const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
   return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? apply(fn, args) : match);