diff --git a/week1.java b/week1.java
index f3a2717..6f8332a 100644
--- a/week1.java
+++ b/week1.java
@@ -7,8 +7,8 @@ class runLabs {
     public static void main(String[] args) {
         new Lab4();
         new Lab5();
+        new Lab7();
         new Lab6();
-        // new Lab7();
     }
 }
 
@@ -254,11 +254,11 @@ class Lab6 extends Lab {
         new six1();
         System.out.println(String.format("%n"));
         new six3();
-        new six5();
         new six6();
         new six7();
         new six8();
         new six9();
+        new six5();
     }
 
     /**
@@ -289,10 +289,75 @@ class Lab6 extends Lab {
         }
     }
 
+    /**
+     * Number guessing game
+     * Random number between 0 and 99, user guesses and is told higher / lower / correct
+     */
     class six5 extends Exercise {
+        private Random random = new Random();
+
         public six5() {
             super(5);
-            System.out.println(String.format("TODO / NOT IMPLEMENTED until we get stdin working"));
+            System.out.println(String.format("TODO: get stdin working to user can play"));
+            numberGuessingGame();
+            // System.out.println(String.format("Testing randomBetween..."));
+            // int max = 100;
+            // int min = 50;
+            // for (int i=0; i<125; i++) {
+            //     System.out.printf("%d ", randomBetween(min, max));
+            // }
+            // System.out.println(String.format("done."));
+        }
+
+        public void numberGuessingGame() {
+            final boolean SUPER_ADVANCED_AI = true;
+            final int HIGHEST = 99;
+            final int MAX_GUESSES = 10;
+
+            int chosenNumber = random.nextInt(HIGHEST+1);
+            int guess = random.nextInt(HIGHEST+1);
+            // super advanced AI section
+            int maxPossible = HIGHEST+1;
+            int minPossible = 0;
+
+            String guesses = "guess"; // for correct plurals
+
+            System.out.printf("Guessing...\t");
+            for (int i = 0; i < MAX_GUESSES; i++ ) {
+                System.out.printf("%d", guess);
+                if (guess == chosenNumber) {
+                    System.out.println(String.format("\nYou guessed right after %d %s! It was indeed %d",
+                                                     i+1, guesses, chosenNumber));
+                    return;
+                }
+                guesses = "guesses"; // didn't get it on the first try
+                if (guess < chosenNumber) {
+                    System.out.printf("↑\t");
+                    if (guess > minPossible) { minPossible = guess; }
+                } else {
+                    System.out.printf("↓\t");
+                    if (guess < maxPossible) {
+                        maxPossible = guess;
+                    }
+                }
+
+                // The better approach is to guess halfway between minPossible and maxPossible
+                // but that's kinda boring and robotic
+                if (SUPER_ADVANCED_AI) {
+                    guess = randomBetween(minPossible, maxPossible);
+                }
+                // TODO change the behaviour so it doesn't guess the same number in a row
+            }
+
+            System.out.println(String.format("\nThe answer was: %d. Better luck next time!", chosenNumber));
+
+        }
+
+        public int randomBetween(int min, int max) {
+            if (min < 0) { min = 0; }
+            if (max == 0) { return 0; }
+            // System.out.printf(" random.nextInt(%d - %d) + %d ", max, min, min);
+            return (random.nextInt(max - min) + min);
         }
     }
     /**