diff --git a/app/calculator.py b/app/calculator.py
index 4b767c9a..fc0e8845 100644
--- a/app/calculator.py
+++ b/app/calculator.py
@@ -16,3 +16,6 @@ def divide(x, y):
 
     def add2(x,y,z):
         return x+y+z
+
+    def subtract2(x, y,z):
+        return x - y - z