diff --git a/calculator.c b/calculator.c
index 832dfd2..5f5b2e6 100644
--- a/calculator.c
+++ b/calculator.c
@@ -4,8 +4,9 @@ void add(int a, int b)
 {
     printf("a + b = %d\n", a + b);
 }
-void sub()
+void sub(int a, int b)
 {
+    printf("a-b= %d\n", a - b);
 }
 void mul()
 {