Scratch exercise 60

Domino effect

In this game you will make the cat walk around and cause 4 balls to bounce around the stage.


1. Create a new Scratch game .. File>New


2. Right-click on the cat sprite beneath the stage and re-name it "Cat" ..


3. Add these scripts to the cat ..


4. Press the "B" key to try out the arrow keys. If your cat is walking OK press "E" to end.


5. Save your game .. File>Save as. Give it a name like "cat and balls".

6. Click the "paint new sprite" button under the stage and paint an orange ball. You can use the biggest paint brush size to do this with one click ..


Click "OK", and re-name it "ball 1" then click on the scripts tab and add this script to it ..



7. Press "B" to start your game. Use the arrow keys to make your cat touch the orange ball. The ball should bounce around the stage.


8. Press "E" to end your game. Now right-click "ball 1" under the stage to duplicate (copy) it ..


9. Make 4 balls and name them so you have "ball 1", "ball 2", "ball 3", and "ball 4".

Edit their costumes so that each ball is a different colour.


10. Change the script for "ball 2" so it moves when it is touching "ball1".

Change the script for "ball 3" so it moves when it is touching "ball 2".

Change the script for "ball 4" so it moves when it is touching "ball 3".


8. Save you game again. This time because you've already saved and named your game once, just select "File>Save".


9. Press the "B" key to start your game. Use the arrow keys to move the cat towards the orange ball ("ball 1"). Watch how the balls interact with each other.


10. Press the "E" key to stop your game.


11. Well done. You've finished. Can you change the speed and distance for each ball?