diff --git a/src/main/c/main_taschenrechner.c b/src/main/c/main_taschenrechner.c
index 79ece02..9727e18 100644
--- a/src/main/c/main_taschenrechner.c
+++ b/src/main/c/main_taschenrechner.c
@@ -10,3 +10,7 @@ int add(int a, int b) {
     return a+b;
     
 }
+
+int minus (int a, int b){
+    return a - b;
+}
diff --git a/src/main/c/taschenrechner.h b/src/main/c/taschenrechner.h
index 1261fd7..0ebc004 100644
--- a/src/main/c/taschenrechner.h
+++ b/src/main/c/taschenrechner.h
@@ -3,4 +3,6 @@
 
 int add(int a, int b);
 
+int minus(int a, int b);
+
 #endif // TASCHENRECHNER_H