Take a large sheet of squared paper (half cm squares work well)
- Colour in a square which is near to the centre of the paper with a red crayon
Repeat the following instructions:
- Colour in blue all the squares touching a red square along one side only;
- Colour in yellow all the squares touching a blue square along one side only;
- Colour in red all the squares touching a yellow square along one side only;
Keep repeating these three instructions until you run out of paper!
If you would prefer to do this activity online where each stage is checked by the computer, try Fractal Mosaic.