diff --git a/src/multiplication.c b/src/multiplication.c
index 24be7fd..b583823 100644
--- a/src/multiplication.c
+++ b/src/multiplication.c
@@ -44,5 +44,9 @@ int multiply_string(const char* str, int factor) {
     return result;
 }
 
+int multiply_by_sum(int num1, int num2) {
+    return num1 * (num2 + 1);
+}
+
     
 
diff --git a/src/multiplication.h b/src/multiplication.h
index 1e6fddf..77be6d8 100644
--- a/src/multiplication.h
+++ b/src/multiplication.h
@@ -9,6 +9,7 @@ int multiply_by_ten(int a);
 float multiply_by_percentage(float num, float percentage);
 int multiply_by_random(int num);
 int multiply_string(const char* str, int factor);
+int multiply_by_sum(int num1, int num2);
 
 
 #endif // MULTIPLICATION_H