The Number Crunching Machine

Problem | Teachers' Notes | Hint | Solution | Printable page |
Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

Why do this problem?

This problem is an amusing and thought-provoking way of practising addition, subtraction, multiplication and division. The results are divers enough to keep learners working for a considerable time and to encourage methodical working. This sheet might be helpful.


Key questions

What operation do you need to do next?
Would it be a good idea to jot down your calculations as you go?
What numbers have you put in so far?
Have you made a list of the numbers you have already done?
How many numbers have you found that come out unchanged?

Possible extension

Learners could make their own number-crunching machine and try it out on their friends.


Possible support

Suggest trying with different numbers below $50$. It may help to make a version going across the page with arrows or you could use this sheet.

Published July 2003,August 2003.