diff --git a/app/calculator.js b/src/calculator.js
similarity index 100%
rename from app/calculator.js
rename to src/calculator.js
diff --git a/app/calculator.test.js b/src/calculator.test.js
similarity index 94%
rename from app/calculator.test.js
rename to src/calculator.test.js
index 8e78fa6..2943fbc 100644
--- a/app/calculator.test.js
+++ b/src/calculator.test.js
@@ -37,5 +37,5 @@ test('divide function', () => {
   expect(divide(1.0, 2.0)).toBe(0.5);
   expect(divide(0, 2.0)).toBe(0);
   expect(divide(-4, 2.0)).toBe(-2.0);
-  // expect(divide(2.0, 0)).toBe('Cannot divide by 0');
+  expect(divide(2.0, 0)).toBe('Cannot divide by 0');
 });