diff --git a/src/multiplication.c b/src/multiplication.c
index d9cca83..1b3717e 100644
--- a/src/multiplication.c
+++ b/src/multiplication.c
@@ -14,6 +14,9 @@ int multiply_three_integers(int a, int b, int c) {
     return a * b * c;
 }
 
+int multiply_left_shift(int a, int b) {
+    return a << b;
+}
 
 
 
diff --git a/src/multiplication.h b/src/multiplication.h
index 441d28a..c4fdd6b 100644
--- a/src/multiplication.h
+++ b/src/multiplication.h
@@ -3,5 +3,7 @@
 extern double multi(double ein1, double ein2);
 double square(double x);
 int multiply_three_integers(int a, int b, int c);
+int multiply_left_shift(int a, int b);
+
 #endif // MULTIPLICATION_H