Ability to convert numbers to numeral adverbs

src/index.js

@@ -3,5 +3,6 @@
 module.exports = {
     toOrdinal: require('./toOrdinal'),
     toWords: require('./toWords'),
-    toWordsOrdinal: require('./toWordsOrdinal')
+    toWordsOrdinal: require('./toWordsOrdinal'),
+    toWordsNumeralAdverb: require('./toWordsNumeralAdverb')
 };

src/toWordsNumeralAdverb.js

@@ -0,0 +1,29 @@
+'use strict';
+
+var toWords = require('./toWords');
+
+numeralAdverbsLessThanFour = {
+    one: 'once',
+    two: 'twice',
+    three: 'thrice'
+}
+
+/**
+ * Converts a number into a numeral adverb.
+ * @example toWordsNumeralAdverb(12) => 'twelve times'
+ * @example toWordsNumeralAdverb(3, false) => 'thrice'
+ * @example toWordsNumeralAdverb(3, true) => 'three times'
+ * @param {number|string} number
+ * @param {boolean} ignoreThrice if thrice should be ignored for those who don't like it 
+ * @returns {string}
+ */
+function toWordsNumeralAdverb(number, ignoreThrice = false) {
+    var words = toWords(number);
+    if (numeralAdverbsLessThanFour.hasOwnProperty(words) && (number !== 3 || !ignoreThrice)) {
+        return numeralAdverbsLessThanFour[words];
+    } else {
+        return words + ' times';
+    }
+}
+
+module.exports = toWordsNumeralAdverb;