- Make a grid of 0's. Really you just need a border of 0's, but filling an area is faster. It should be twice as wide as tall.
- Select cell B2, and give it the formula =MOD(A1+c1,10).
- Copy B2 and paste it into all the cells in the grid except for the top row and the left and right columns.
- Now they are all adding the values of the two cells diagonally above them. Just put a "1" in the middle of the top row and see what happens.
- To color the different digits, click Format, Conditional Formatting, and make some stuff up.
- I changed the font color to white and clicked File > Web Page Preview:
You could do some fun experiments with this, leading kids toward the idea of cellular automata!