## Welcome to Plus magazine!

The Mayan civilisation brought forth many great things — including this clever way of making a right angle.

How many rational solutions can you find on a doughnut?

The Fields medallist reveals the beauty of numbers, how he drew inspiration from Sanskrit maths and a Rubik's cube, and how his maths fits with his tabla playing.

*Image courtesy NASA.*

Asking good questions is an important part of doing maths. But what makes a good question?

Sometimes a piece of maths can be so neat and elegant, it makes you want to shout "eureka!" even if you haven't produced it yourself. One of our favourite examples is the art gallery problem.

Books, brains, computers — information comes in many guises. But what exactly *is* information?

In the game of Nim one player always has a winning strategy — it depends on a weird way of adding binary numbers.