roundTo( ) | JavaScript function | A JavaScript function that returns a float to a given number of decimal places, can also transpose the decimal place if needed.

roundTo.js

/**
 * RoundTo
 * ------------------------------------------------------------------------
 * roundTo()
 * @version 1.0 | April 18th 2013
 * @author  Beau Charman | @beaucharman | http://www.beaucharman.me
 * @link    https://gist.github.com/beaucharman/5401683
 * @param   {float}   n   | the subject number we are rounding
 * @param   {integer} d   | the number to decimal places to round to
 * @param   {string}  dir | 'round', 'floor' or 'ceil'
 * @param   {integer} t   | the number to decimal places to transpose to
 * @return  {float}
 *
 * A JavaScript function that returns a float to a given number
 * of decimal places, can also transpose the decimal place if needed.
 * ------------------------------------------------------------------------ */
var roundTo = function(n, d, dir, t) {
  'use strict';
  if (!n || (typeof n !== 'number')) {
    return false;
  }
  var r, e;
  d = d || 2;
  t = (!t) ? d : d - t;
  d = Math.pow(10, d);
  t = Math.pow(10, t);
  e = n * d;
  r = (function() {
    switch (dir.toLowerCase()) {
      case 'floor': return Math.floor(e);
      case 'ceil':  return Math.ceil(e);
      default:      return Math.round(e);
    }
  }());
  return r / t;
};

// example
console.log(roundTo(56.2223, 2, 'ceil', 0));
// => 56.23