Made "use strict" Global

Author: PatOnTheBack

maths/factorial.js

@@ -11,9 +11,10 @@
  https://en.wikipedia.org/wiki/factorial
 */
 
+"use strict";
+
 function calc_range(num) {
  // Generate a range of numbers from 1 to `num`.
- "use strict";
  var i = 1;
  var range = [];
  while (i <= num) {
@@ -24,7 +25,6 @@ function calc_range(num) {
 }
 
 function calc_factorial(num) {
- "use strict";
  var factorial;
  var range = calc_range(num);