diff --git a/08_calculator/calculator.js b/08_calculator/calculator.js
index 5808d01..3b880a9 100644
--- a/08_calculator/calculator.js
+++ b/08_calculator/calculator.js
@@ -8,28 +8,47 @@ const subtract = function(num1, num2) {
   return total;
 };
 
-const sum = function() {
+const sum = function(numList) {
 	  let total = 0;
 
-    for (i = 0; i < numList.length; i++) {
+    for (let i = 0; i < numList.length; i++) {
         total += parseInt(numList[i]);
     }
     
     return total;
 };
 
-const multiply = function(num1, num2) {
-  let total = num1 * num2;
+const multiply = function(numList) {
+  let total = 1;
+  
+  for (let i = 0; i < numList.length; i++) {
+    total *= parseInt(numList[i]);
+  }
+
   return total;
 };
 
-const power = function() {
-	
+const power = function(num, power) {
+	//empty variable for total
+  let total = 1;
+  //for loop to repeat num by power
+  for (let i = 0; i < power; i++) {
+    //multiply each num with empty variable 
+    total *= num;
+  }
+  return total; 
 };
 
-const factorial = function() {
-	
-};
+const factorial = function(num) {
+  //empty variable for total
+  let total = 1;
+  //for loop to continue until num is reached
+  for (let i = 1; i <= num; i++) {
+    //multiply total with the i variable, which starts at 1, and repeats until num 
+    total *= i;
+  }
+  return total; 
+  };
 
 // Do not edit below this line
 module.exports = {
diff --git a/08_calculator/calculator.spec.js b/08_calculator/calculator.spec.js
index dc317ec..c82a04b 100644
--- a/08_calculator/calculator.spec.js
+++ b/08_calculator/calculator.spec.js
@@ -5,73 +5,73 @@ describe('add', () => {
 		expect(calculator.add(0,0)).toBe(0);
 	});
 
-	test.skip('adds 2 and 2', () => {
+	test('adds 2 and 2', () => {
 		expect(calculator.add(2,2)).toBe(4);
 	});
 
-	test.skip('adds positive numbers', () => {
+	test('adds positive numbers', () => {
 		expect(calculator.add(2,6)).toBe(8);
 	});
 });
 
 describe('subtract', () => {
-	test.skip('subtracts numbers', () => {
+	test('subtracts numbers', () => {
 		expect(calculator.subtract(10,4)).toBe(6);
 	});
 });
 
 describe('sum', () => {
-	test.skip('computes the sum of an empty array', () => {
+	test('computes the sum of an empty array', () => {
 		expect(calculator.sum([])).toBe(0);
 	});
 
-	test.skip('computes the sum of an array of one number', () => {
+	test('computes the sum of an array of one number', () => {
 		expect(calculator.sum([7])).toBe(7);
 	});
 
-	test.skip('computes the sum of an array of two numbers', () => {
+	test('computes the sum of an array of two numbers', () => {
 		expect(calculator.sum([7,11])).toBe(18);
 	});
 
-	test.skip('computes the sum of an array of many numbers', () => {
+	test('computes the sum of an array of many numbers', () => {
 		expect(calculator.sum([1,3,5,7,9])).toBe(25);
 	});
 });
 
 describe('multiply', () => {
-	test.skip('multiplies two numbers', () => {
+	test('multiplies two numbers', () => {
 		expect(calculator.multiply([2,4])).toBe(8);
 	});
 
-	test.skip('multiplies several numbers', () => {
+	test('multiplies several numbers', () => {
 		expect(calculator.multiply([2,4,6,8,10,12,14])).toBe(645120);
 	});
 });
 
 describe('power', () => {
-	test.skip('raises one number to the power of another number', () => {
+	test('raises one number to the power of another number', () => {
 		expect(calculator.power(4,3)).toBe(64); // 4 to third power is 64
 	});
 });
 
 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);
 	});
 });