Nodejs Utililty Methods Number Calculate

var expect = chai.expect;
Number.prototype.square = function () {
    "use strict";
    return this * this;
};

Number.prototype.square = function() {
  return this * this;
};

Number.prototype.step = function (to, add_remove_step) {
  var from = this.valueOf();
  var ch = add_remove_step.match(/[\+,\-]/g)[0];
  var i = from;
  var arr = [];
  if (ch === '+') {
    while (i <= to) {
      arr.push(i);
      i = i + parseInt(add_remove_step);
...

Number.prototype.subNum = function(n){
  var f_x = parseFloat(this);
  if (isNaN(f_x)){
    return false;
  f_x = Math.floor(f_x*Math.pow(10,n)+0.0001)/Math.pow(10,n);
  var s_x = f_x.toString();
  var pos_decimal = s_x.indexOf('.');
  if (pos_decimal < 0){
...

Number.prototype.succ = function() {
    return this + 1;
};

Number.prototype.tan = function() {
    return Math.tan(this);

function Number(){
  this.start = 20
  this.testNumber();
  this.answer = 1
};
Number.prototype.testNumber = function(){
  var i = 1;
  var start = this.start;
  while(i <= 20){
...

Number.prototype.trim = function(a, b) {
  var min = Math.min(a, b),
      max = Math.max(a, b);
  return Math.min(Math.max(parseInt(this, 10), min), max);
};

Number.prototype.tween = function(target, position){
  return this + (target-this) * position;
};

Number.prototype.twos = function(n) {
  if (this >= 0) {return pad(this.toString(2),n)}
  var max = Math.pow(2,n-1);
  return "1" + pad((max + this).toString(2),n-1)
function pad(num, size) {
    var s = "00000000000000000000" + num;
    return s.substr(s.length-size);
Number.prototype.twos = function(n) {
  var ret = "";
  while(n)
    ret += ( (this >> --n) & (1) );
  return ret;
};