diff --git a/05_sumAll/sumAll.js b/05_sumAll/sumAll.js
index 00880c7..875873d 100644
--- a/05_sumAll/sumAll.js
+++ b/05_sumAll/sumAll.js
@@ -1,6 +1,18 @@
-const sumAll = function() {
+const sumAll = function (number1, number2) {
+  if (number1 < 0 || number2 < 0) return 'ERROR'
+  if (typeof number1 !== 'number' || typeof number2 !== 'number') return 'ERROR'
 
-};
+  let sum = 0
+
+  const start = Math.min(number1, number2)
+  const end = Math.max(number1, number2)
+
+  for (let i = start; i <= end; i++) {
+    sum += i
+  }
+
+  return sum
+}
 
 // Do not edit below this line
-module.exports = sumAll;
+module.exports = sumAll
diff --git a/05_sumAll/sumAll.spec.js b/05_sumAll/sumAll.spec.js
index 1a9fb7c..a865931 100644
--- a/05_sumAll/sumAll.spec.js
+++ b/05_sumAll/sumAll.spec.js
@@ -2,21 +2,21 @@ const sumAll = require('./sumAll')
 
 describe('sumAll', () => {
   test('sums numbers within the range', () => {
-    expect(sumAll(1, 4)).toEqual(10);
-  });
-  test.skip('works with large numbers', () => {
-    expect(sumAll(1, 4000)).toEqual(8002000);
-  });
-  test.skip('works with larger number first', () => {
-    expect(sumAll(123, 1)).toEqual(7626);
-  });
-  test.skip('returns ERROR with negative numbers', () => {
-    expect(sumAll(-10, 4)).toEqual('ERROR');
-  });
-  test.skip('returns ERROR with non-number parameters', () => {
-    expect(sumAll(10, "90")).toEqual('ERROR');
-  });
-  test.skip('returns ERROR with non-number parameters', () => {
-    expect(sumAll(10, [90, 1])).toEqual('ERROR');
-  });
-});
+    expect(sumAll(1, 4)).toEqual(10)
+  })
+  test('works with large numbers', () => {
+    expect(sumAll(1, 4000)).toEqual(8002000)
+  })
+  test('works with larger number first', () => {
+    expect(sumAll(123, 1)).toEqual(7626)
+  })
+  test('returns ERROR with negative numbers', () => {
+    expect(sumAll(-10, 4)).toEqual('ERROR')
+  })
+  test('returns ERROR with non-number parameters', () => {
+    expect(sumAll(10, '90')).toEqual('ERROR')
+  })
+  test('returns ERROR with non-number parameters', () => {
+    expect(sumAll(10, [90, 1])).toEqual('ERROR')
+  })
+})