diff --git a/08_calculator/calculator.js b/08_calculator/calculator.js
index 12dd568..cebeaf5 100644
--- a/08_calculator/calculator.js
+++ b/08_calculator/calculator.js
@@ -24,8 +24,11 @@ const power = function(a, x) {
 	return 4 ** 3;
 };
 
-const factorial = function() {
-	
+const factorial = function(a) {
+	if (a <= 1) {
+    return 1;
+  }
+  return a * factorial(a - 1);
 };
 
 // Do not edit below this line
diff --git a/08_calculator/calculator.spec.js b/08_calculator/calculator.spec.js
index 119673a..59956fe 100644
--- a/08_calculator/calculator.spec.js
+++ b/08_calculator/calculator.spec.js
@@ -55,23 +55,23 @@ describe('power', () => {
 });
 
 describe('factorial', () => {
-  test.skip('computes the factorial of 0', () => {
+  test('computes the factorial of 0', () => {
     expect(calculator.factorial(0)).toBe(1); // 0! = 1
   });
 
-  test.skip('computes the factorial of 1', () => {
+  test('computes the factorial of 1', () => {
     expect(calculator.factorial(1)).toBe(1);
   });
 
-  test.skip('computes the factorial of 2', () => {
+  test('computes the factorial of 2', () => {
     expect(calculator.factorial(2)).toBe(2);
   });
 
-  test.skip('computes the factorial of 5', () => {
+  test('computes the factorial of 5', () => {
     expect(calculator.factorial(5)).toBe(120);
   });
 
-  test.skip('computes the factorial of 10', () => {
+  test('computes the factorial of 10', () => {
     expect(calculator.factorial(10)).toBe(3628800);
   });
 });