Adds comment

foaly-nr1 · foaly-nr1 · commit c3faf46c5113 · 2017-03-02T11:05:00.000Z
diff --git a/src/Symfony/Component/Form/Extension/Core/DataTransformer/NumberToLocalizedStringTransformer.php b/src/Symfony/Component/Form/Extension/Core/DataTransformer/NumberToLocalizedStringTransformer.php
@@ -266,6 +266,7 @@ private function round($number)
         if (null !== $this->precision && null !== $this->roundingMode) {
             // shift number to maintain the correct scale during rounding
             $roundingCoef = pow(10, $this->precision);
+            // string representation to avoid rounding errors, similar to bcmul()
             $number = (string) ($number * $roundingCoef);
 
             switch ($this->roundingMode) {
