diff --git a/src/math.ts b/src/math.ts
index 8d9b8a2..8559ea5 100755
--- a/src/math.ts
+++ b/src/math.ts
@@ -1,3 +1,7 @@
 export function add(a: number, b: number): number {
   return a + b;
 }
+
+export function subtract(a: number, b: number): number {
+  return a - b;
+}