4JJ used the skills they have been learning in maths this week to work systematically on this interactive problem.

By trying each number in sequence to find which lights it lit, they recorded their findings on a hundred square.

Eventually, we decided that these were the rules for each light to be lit:

Yellow – number smaller than 31

Green – odd number

Red – numbers with odd tens (10s, 30s, 50s, etc)

Blue – multiples of 5

Can you use the machine to test these theories and make predictions about which numbers will light which lights?