This tutorial will show you how to teach children to program an aquarium with Scratch. Fish will move around an underwater scene at different speeds.

The main programming concept covered is a repeat loop.

Optional challenge activities are

  • Create multiple fish
  • Create a fish which moves around with the mouse
  • Add bubble sounds
  • Change the costume of some fish as they swim

Scratch is developed by the Lifelong Kindergarten Group at the MIT Media Lab. See

Click here to go to the presentation used in this video.