diff --git a/src/main/java/com/booleanuk/core/Exercise.java b/src/main/java/com/booleanuk/core/Exercise.java
index 0f97fe4..0f98f67 100644
--- a/src/main/java/com/booleanuk/core/Exercise.java
+++ b/src/main/java/com/booleanuk/core/Exercise.java
@@ -1,9 +1,11 @@
 package com.booleanuk.core;
 
+import java.util.Arrays;
+
 public class Exercise {
-    public int[] numsZeroToThree;
-    public int[] numsFiveToTen;
-    public int[] countdown;
+    public int[] numsZeroToThree = new int[4];
+    public int[] numsFiveToTen = new int[6];
+    public int[] countdown = new int[4];
 
     public int[] favouriteNumbers = {1, 2, 4, 5, 7, 8, 10};
 
@@ -11,35 +13,48 @@ public class Exercise {
 
     public void stepOne() {
         // TODO: 1. Write a for loop that adds the numbers 0 to 3 to the numsZeroToThree array
-
-
+        for (int i = 0; i < 4; i++){
+            this.numsZeroToThree[i] = i;
+        }
     }
 
     public void stepTwo() {
         // TODO: 2. Write a for loop that adds the numbers 5 to 10 to the numsFiveToTen array
-
-
+        int j = 5;
+        for (int i = 0; i < 6; i++){
+            this.numsFiveToTen[i] = j;
+            j++;
+        }
     }
 
     public void stepThree() {
         // TODO: 3. Write a for loop that adds the numbers 3 to 0 (in that order) to the countdown array
-
+        int j = 3;
+        for (int i = 0; i < 4; i++){
+            this.countdown[i] = j;
+            j--;
+        }
 
     }
 
     public boolean stepFour(int num) {
         // TODO: 6. Write a for loop that checks if num is in the favouriteNumbers array
-
-
-
+        for(int i = 0; i < this.favouriteNumbers.length; i++){
+            if (this.favouriteNumbers[i] == num){
+                return true;
+            }
+        }
         return false;
     }
 
     public boolean stepFive(String hobby) {
         // TODO 5. Write a for loop that checks if the hobby String is in the myHobbies array
-
-
-
+        for (int i = 0; i < this.myHobbies.length; i++){
+            if (hobby == this.myHobbies[i]){
+                return true;
+            }
+        }
         return false;
     }
+
 }
diff --git a/src/main/java/com/booleanuk/extension/Extension.java b/src/main/java/com/booleanuk/extension/Extension.java
index 8b9d4a6..0661405 100644
--- a/src/main/java/com/booleanuk/extension/Extension.java
+++ b/src/main/java/com/booleanuk/extension/Extension.java
@@ -1,12 +1,16 @@
 package com.booleanuk.extension;
 
 public class Extension {
-    public int[] numsEven;
+    public int[] numsEven = new int[4];
 
     public void stepOne() {
         // TODO: 1. Write a for loop that adds all the even numbers between 0 and 6 (0, 2, 4, 6) to evenNums
-
-
-        
+        int position = 0;
+        for (int i = 0; i < 7; i++){
+            if ((i%2) == 0){
+                this.numsEven[position]=i;
+                position++;
+            }
+        }
     }
 }