diff --git a/index.js b/index.js
index 35be089e46ddd72e675f5f8d861fb6a23de2bb8a..80d3cb399d69500993779430df426548ac16365d 100644
--- a/index.js
+++ b/index.js
@@ -1,4 +1,12 @@
-module.exports = function addNumbers(a, b) {
-  // aaaa
+function addNumbers(a, b) {
   return a + b;
 }
+
+function subNumbers(a, b) {
+  return addNumbers(a, -b);
+}
+
+module.exports = {
+  addNumbers,
+  subNumbers,
+}
diff --git a/index.test.js b/index.test.js
index b699c9a292e9bf8b3f0e77facc91483c42292cb4..e230d9f8219ed1bd5921b8ef2bd209fbf6a9a54f 100644
--- a/index.test.js
+++ b/index.test.js
@@ -1,4 +1,4 @@
-const addNumbers = require('./index');
+const { addNumbers, subNumbers } = require('./index');
 
 test('adds 1 + 2 to equal 3', () => {
   expect(addNumbers(1, 2)).toBe(3);
@@ -7,3 +7,11 @@ test('adds 1 + 2 to equal 3', () => {
 test('adds -1 + 2 to equal 1', () => {
   expect(addNumbers(-1, 2)).toBe(1);
 });
+
+test('subs 1 - 2 to equal -1', () => {
+  expect(subNumbers(1, 2)).toBe(-1);
+});
+
+test('subs -1 - 2 to equal -3', () => {
+  expect(subNumbers(-1, 2)).toBe(-3);
+});