diff --git a/calculator/calculator.app.js b/calculator/calculator.app.js
index 268c81d..c520e80 100644
--- a/calculator/calculator.app.js
+++ b/calculator/calculator.app.js
@@ -195,7 +195,7 @@ function fixFloat(n) {
 
 function addSeparators(s) {
   var parts = s.split(".");
-  parts[0] = parts[0].replace(/\B(?=(\d{3})+(?!\d))/g, "'");
+  parts[0] = parts[0].replace(/\B(?=(\d{3})+(?!\d))/g, ",");
   return parts.join(".");
 }