Drawing the right diagram can help you to prove a result about the angles in a line of squares.

DNA profiling is an invaluable tool for the police. However, when it comes to probability, things aren't always as straightforward as they seem.

Which countries have the most naturally athletic populations?

Can you make sense of the charts and diagrams that are created and used by sports competitors, trainers and statisticians?

Can you find the missing constants from these not-quite-so-obvious definite integrals?

Can you find a polynomial function whose first derivative is equal to the function?

Can you explain what is going on in these puzzling number tricks?

Gabriel multiplied together some numbers and then erased them. Can you figure out where each number was?

Are you at risk of being a victim of crime? How does your perception of that risk compare with the facts and figures?

Can you match the cards and figure out whether the tabloid headlines can be trusted?

99% of people who have measles have spots. Ben has spots. Do you think he has measles?

I'd be very surprised if I had three children all with the same birthday, but I read in the paper that it happened to one family...

In 1% of cases, an HIV test gives a positive result for someone who is HIV negative. How likely is it that someone who tests positive has HIV?

Four jewellers share their stock. Can you work out the relative values of their gems?

A lune is the area left when part of a circle is cut off by another circle. Can you work out the area?

What graphs can you make by transforming sine, cosine and tangent graphs?

Here are some more triangle equations. Which are always true?

Can you find equations for cubic curves that have specific features?