diff --git a/src/splitInteger.test.js b/src/splitInteger.test.js
index 24003dd5..06d0ae18 100644
--- a/src/splitInteger.test.js
+++ b/src/splitInteger.test.js
@@ -3,11 +3,62 @@
 const splitInteger = require('./splitInteger');
 
 test(`should split a number into equal parts
-  if a value is divisible by a numberOfParts`, () => {});
+  if a value is divisible by a numberOfParts`, () => {
+  expect(splitInteger(9, 3)).toEqual([3, 3, 3]);
+  expect(splitInteger(10, 2)).toEqual([5, 5]);
+  expect(splitInteger(0, 4)).toEqual([0, 0, 0, 0]);
+});
 
 test(`should return a part equals to a value
-  when splitting into 1 part`, () => {});
+  when splitting into 1 part`, () => {
+  expect(splitInteger(5, 1)).toEqual([5]);
+  expect(splitInteger(0, 1)).toEqual([0]);
+  expect(splitInteger(1000000, 1)).toEqual([1000000]);
+});
 
-test('should sort parts ascending if they are not equal', () => {});
+test('should sort parts ascending if they are not equal', () => {
+  expect(splitInteger(10, 3)).toEqual([3, 3, 4]);
+  expect(splitInteger(7, 3)).toEqual([2, 2, 3]);
+  expect(splitInteger(11, 4)).toEqual([2, 3, 3, 3]);
+});
 
-test('should add zeros if value < numberOfParts', () => {});
+test('should add zeros if value < numberOfParts', () => {
+  expect(splitInteger(3, 5)).toEqual([0, 0, 1, 1, 1]);
+  expect(splitInteger(1, 4)).toEqual([0, 0, 0, 1]);
+  expect(splitInteger(0, 3)).toEqual([0, 0, 0]);
+});
+
+test('should return an array of numbers', () => {
+  const result = splitInteger(10, 3);
+
+  expect(Array.isArray(result)).toBe(true);
+  result.forEach((part) => expect(typeof part).toBe('number'));
+});
+
+test('should return an array with the correct number of parts', () => {
+  expect(splitInteger(10, 3)).toHaveLength(3);
+  expect(splitInteger(7, 5)).toHaveLength(5);
+  expect(splitInteger(0, 4)).toHaveLength(4);
+});
+
+test('should have parts that sum to the original value', () => {
+  const cases = [
+    [9, 3],
+    [10, 3],
+    [7, 5],
+    [1000000, 7],
+    [0, 4],
+  ];
+
+  cases.forEach(([value, parts]) => {
+    const result = splitInteger(value, parts);
+    const sum = result.reduce((acc, n) => acc + n, 0);
+
+    expect(sum).toBe(value);
+  });
+});
+
+test('should handle large numbers correctly', () => {
+  expect(splitInteger(1000000, 4)).toEqual([250000, 250000, 250000, 250000]);
+  expect(splitInteger(1000001, 4)).toEqual([250000, 250000, 250000, 250001]);
+});