diff --git a/src/multiplication.c b/src/multiplication.c
index 7b29b87..30e335c 100644
--- a/src/multiplication.c
+++ b/src/multiplication.c
@@ -6,6 +6,12 @@ double multi( double ein1, double ein2) {
     return (ein1 * ein2);
 }
 
+double square(double x) {
+    return x * x;
+}
+
+
+
 
     
 
diff --git a/src/multiplication.h b/src/multiplication.h
index a8570d0..c16d9ca 100644
--- a/src/multiplication.h
+++ b/src/multiplication.h
@@ -1,4 +1,6 @@
 #ifndef MULTIPLICATION_H
 #define MULTIPLICATION_H
 extern double multi(double ein1, double ein2);
+double square(double x);
 #endif // MULTIPLICATION_H
+