diff --git a/08_calculator/solution/calculator-solution.spec.js b/08_calculator/solution/calculator-solution.spec.js
index c99993b..453707c 100644
--- a/08_calculator/solution/calculator-solution.spec.js
+++ b/08_calculator/solution/calculator-solution.spec.js
@@ -21,30 +21,30 @@ describe('subtract', () => {
 });
 
 describe('sum', () => {
-  test('computes the sum of an empty parameter', () => {
-    expect(calculator.sum()).toBe(0);
+  test('computes the sum of an empty array', () => {
+    expect(calculator.sum([])).toBe(0);
   });
 
-  test('computes the sum of one number', () => {
-    expect(calculator.sum(7)).toBe(7);
+  test('computes the sum of an array of one number', () => {
+    expect(calculator.sum([7])).toBe(7);
   });
 
-  test('computes the sum of two numbers', () => {
-    expect(calculator.sum(7, 11)).toBe(18);
+  test('computes the sum of an array of two numbers', () => {
+    expect(calculator.sum([7, 11])).toBe(18);
   });
 
-  test('computes the sum of many numbers', () => {
-    expect(calculator.sum(1, 3, 5, 7, 9)).toBe(25);
+  test('computes the sum of an array of many numbers', () => {
+    expect(calculator.sum([1, 3, 5, 7, 9])).toBe(25);
   });
 });
 
 describe('multiply', () => {
   test('multiplies two numbers', () => {
-    expect(calculator.multiply(2, 4)).toBe(8);
+    expect(calculator.multiply([2, 4])).toBe(8);
   });
 
   test('multiplies several numbers', () => {
-    expect(calculator.multiply(2, 4, 6, 8, 10, 12, 14)).toBe(645120);
+    expect(calculator.multiply([2, 4, 6, 8, 10, 12, 14])).toBe(645120);
   });
 });