diff --git a/Program.fs b/Program.fs
index 23a8b17..fcbe71f 100644
--- a/Program.fs
+++ b/Program.fs
@@ -230,7 +230,7 @@ let applyOp op left right =
     | Star, Number x, Number y -> Number (x * y)
     | Slash, Number x, Number y -> Number (x / y)
     | Percent, Number x, Number y -> Number (x % y)
-    | SlashSlash, Number x, Number y -> Number (floor x / y)
+    | SlashSlash, Number x, Number y -> Number (floor (x / y))
     | Caret, Number x, Number y -> Number (x ** y)
     | _, Fail _, _ -> left
     | _, _, Fail _ -> right