geometry
How calculating the height of a frustum gave a glimpse of the mathematical frontier. 

The division of plant cells is governed by their shape – just one example of how maths may reveal the fundamental laws underlying biology. 

How to derive the famous quadratic formula from pictures, just like the Babylonians did. 

Euclid's fourth axiom says that all right angles are equal. But isn't that obvious? 

This week would have been the 100th birthday of Martin Gardner, who is deservedly credited with turning on several generations of people worldwide to the pleasures of maths! To mark the occasion here are some favourite puzzles that, apart from being fun, also lead to some serious maths. 