Bump to v4.14.0.

_createMathOperation.js

@@ -8,13 +8,14 @@ define(['./_baseToNumber', './_baseToString'], function(baseToNumber, baseToStri
    *
    * @private
    * @param {Function} operator The function to perform the operation.
+   * @param {number} [defaultValue] The value used for `undefined` arguments.
    * @returns {Function} Returns the new mathematical operation function.
    */
-  function createMathOperation(operator) {
+  function createMathOperation(operator, defaultValue) {
     return function(value, other) {
       var result;
       if (value === undefined && other === undefined) {
-        return 0;
+        return defaultValue;
       }
       if (value !== undefined) {
         result = value;