In time for pancake day here's a problem about flipping pancakes. It turns out to be surprisingly hard.

Genes normally evolve by tiny mutations, but every now and then something more radical occurs and entire genes along a chromosome get flipped. Understanding gene flipping boils down to solving a problem from pure maths. Colva Roney-Dougal and Vincent Vatter explain, taking us on a journey from waiters sorting pancakes, via one of the richest men in the world, to the genetic similarities of mice and humans.
Did you know that church bell ringers have to memorise sequences of several thousand numbers, and that it can take up to 18 hours to translate these sequences into perfect bell ringing? Burkard Polster and Marty Ross explain why, and explore the maths behind bell ringing.
Lucinda Mathews visualises tricky surfaces
With the credit crunch dominating the news, columnists have been wailing about "chaos in the markets", and "turbulent" share prices. But what does move the markets? Are they deterministic, or a result of chance? Colva Roney-Dougal explores the maths, from chaos to group theory.
Computer scientists prove how long it should take you to solve Rubik's cube
There are many errors that can occur when numbers are written, printed or transferred in any manner. Luckily, there are schemes in place to detect, and in some cases even correct, such errors almost immediately. Emily Dixon takes a break and discovers that codes are not just for sleuths.