How to play What's My Rule?
- Choose a level: one step, two steps or tricky.
- Type a number and press Put it in, or press Suggest a number.
- Look at the table. Can you see a pattern between the In and Out numbers?
- Predict what the machine will do with the next number. Press Reveal the rule to check.
Maths skills this game builds
- Number patterns and rules
- Inverse operations
- Early algebra: function machines
- Predicting and generalising
Tips for parents and carers
- Pick numbers carefully. Trying 0 and 1 often gives clues quickly.
- Ask your child to predict an output before you enter it.
- Swap roles: your child makes up a rule and you try to guess it.
Using What's My Rule? with a group or class
- Ask children to suggest numbers, and type them in yourself. Ask them to predict each output before you reveal it.
- Question to ask: Which number was most helpful to test, and why?
- Children can draw their own table on paper and write a guess for the rule at the bottom.
Frequently asked questions
What is a function machine?
A function machine takes a number, changes it using a rule, and gives a new number. It is a first step towards algebra.
Are the rules always whole numbers?
Most are. A few rules use halving, so you might see a decimal.
Can I choose my own numbers?
Yes. Type any whole number, or press Suggest a number.