diff --git a/05_sumAll/sumAll.js b/05_sumAll/sumAll.js
index 00880c7..f1f3de1 100644
--- a/05_sumAll/sumAll.js
+++ b/05_sumAll/sumAll.js
@@ -1,5 +1,24 @@
-const sumAll = function() {
+const sumAll = function () {
+    if (typeof(arguments[0]) === 'number' && typeof(arguments[1]) === 'number' && arguments[0] >= 0 && arguments[1] >= 0) {
+        let biggerNum = 0, smallerNum = 0;
+        if (arguments[0] > arguments[1]) {
+            biggerNum = arguments[0];
+            smallerNum = arguments[1];
+        } else {
+            biggerNum = arguments[1];
+            smallerNum = arguments[0];
+        }
 
+        let result = 0;
+
+        for (let i = smallerNum; i <= biggerNum; i++) {
+            result += i;
+        }
+
+        return result;
+    }
+
+    return 'ERROR';
 };
 
 // Do not edit below this line
diff --git a/05_sumAll/sumAll.spec.js b/05_sumAll/sumAll.spec.js
index 1a9fb7c..a171e5f 100644
--- a/05_sumAll/sumAll.spec.js
+++ b/05_sumAll/sumAll.spec.js
@@ -4,19 +4,19 @@ describe('sumAll', () => {
   test('sums numbers within the range', () => {
     expect(sumAll(1, 4)).toEqual(10);
   });
-  test.skip('works with large numbers', () => {
+  test('works with large numbers', () => {
     expect(sumAll(1, 4000)).toEqual(8002000);
   });
-  test.skip('works with larger number first', () => {
+  test('works with larger number first', () => {
     expect(sumAll(123, 1)).toEqual(7626);
   });
-  test.skip('returns ERROR with negative numbers', () => {
+  test('returns ERROR with negative numbers', () => {
     expect(sumAll(-10, 4)).toEqual('ERROR');
   });
-  test.skip('returns ERROR with non-number parameters', () => {
+  test('returns ERROR with non-number parameters', () => {
     expect(sumAll(10, "90")).toEqual('ERROR');
   });
-  test.skip('returns ERROR with non-number parameters', () => {
+  test('returns ERROR with non-number parameters', () => {
     expect(sumAll(10, [90, 1])).toEqual('ERROR');
   });
 });