diff --git a/05_sumAll/sumAll.js b/05_sumAll/sumAll.js
index 00880c7..e633118 100644
--- a/05_sumAll/sumAll.js
+++ b/05_sumAll/sumAll.js
@@ -1,5 +1,20 @@
-const sumAll = function() {
-
+const sumAll = function(arg1, arg2) {
+    let sum = 0;
+    if (typeof(arg1) != 'number' || typeof(arg2) != 'number' || arg1 < 0 || arg2 < 0) {
+        return "ERROR";
+    }
+    let small, big;
+    if (arg1 < arg2) {
+        small = arg1;
+        big = arg2;
+    } else {
+        small = arg2;
+        big = arg1;
+    }
+    for (let i = small; i <= big; i++) {
+        sum += i;
+    }
+    return sum;
 };
 
 // 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');
   });
 });