Many of the problems in this feature include proof sorting activities which challenge you to rearrange statements in order to recreate clear, rigorous proofs. There are also a selection of "dodgy proofs" where your challenge is to find out where the logic breaks down.
Plus magazine has a selection of interesting articles about proofs here.
What does it all add up to?
Difference of odd squares
Impossible sums
Adding odd numbers (part 2)
KS5 Proof shorts
Direct logic
We are very grateful to the Heilbronn Institute for Mathematical Research for their generous support for the development of these resources.