diff --git a/lib/fizzbuzz.rb b/lib/fizzbuzz.rb
index 717b0e7..6635816 100644
--- a/lib/fizzbuzz.rb
+++ b/lib/fizzbuzz.rb
@@ -1,6 +1,6 @@
 class Fizzbuzz
   def calculate number
-    if number.to_s.include? '7'
+    if number % 7 ==0
       'GitHub'
     elsif number % 3 == 0 && number % 5 == 0
       'fizzbuzz'