diff --git a/index.html b/index.html
index eb8b358..968fac6 100644
--- a/index.html
+++ b/index.html
@@ -21,9 +21,13 @@
   function minus(a, b) {
     return a-b;
   }
-
+  
   function pow(a, b) {
-    return Math.pow(a,b);
+    return Math.pow(a, b);
+  }
+
+  function abs(a) {
+    return Math.abs(a);
   }
 </script>
 </body>