update elements and fix some bugs

lib/src/iron-range-behavior/iron-range-behavior.html

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 <link rel="import" href="../polymer/polymer.html">
 
 <script>
 
- /** 
+ /**
  * `iron-range-behavior` provides the behavior for something with a minimum to maximum range.
  *
  * @demo demo/index.html
- * @polymerBehavior 
+ * @polymerBehavior
  */
  Polymer.IronRangeBehavior = {
 
   properties: {
 
     /**
      * The number that represents the current value.
      */
     value: {
       type: Number,
@@ skipping 48 matching lines @@
     return (this._clampValue(value) - this.min) / (this.max - this.min);
   },
 
   _clampValue: function(value) {
     return Math.min(this.max, Math.max(this.min, this._calcStep(value)));
   },
 
   _calcStep: function(value) {
    /**
     * if we calculate the step using
-    * `Math.round(value / step) * step` we may hit a precision point issue 
+    * `Math.round(value / step) * step` we may hit a precision point issue
     * eg. 0.1 * 0.2 =  0.020000000000000004
     * http://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html
     *
     * as a work around we can divide by the reciprocal of `step`
     */
-    return this.step ? (Math.round(value / this.step) / (1 / this.step)) : value;
+    // polymer/issues/2493
+    value = parseFloat(value);
+    return this.step ? (Math.round((value + this.min) / this.step) -
+        (this.min / this.step)) / (1 / this.step) : value;
   },
 
   _validateValue: function() {
     var v = this._clampValue(this.value);
     this.value = this.oldValue = isNaN(v) ? this.oldValue : v;
     return this.value !== v;
   },
 
   _update: function() {
     this._validateValue();
     this._setRatio(this._calcRatio(this.value) * 100);
   }
 
 };
 </script>