These three brainteasers challenge students to be resourceful, to think logically and to work systematically. They are designed to be accessible to secondary maths students at Key Stages 3 and 4.
Detailed teachers' notes for this activity are available on our NRICH website.
If you're finding hard to get started, try looking at this hint on our NRICH website.
If you enjoyed this you might also like our KS3 activity Medal Muddle.