What's the risk of passive smoking? Or climate change? How big is the terrorist threat? And should we trust league tables? These issues concern all of us, but it's not always easy to make sense of the barrage of media information. David Spiegelhalter, Winton Professor for the Public Understanding of Risk, gives Plus his take on uncertainty.

John Napier was a clever man indeed. Besides inventing the logarithm, he developed ingenious calculating devices that fully exploit the power of the positional system. In this article Chris Sangwin tells you how to make your own set of Napier's bones and perform mathemagic with an interactive checker board.

Former Plus editor Helen Joyce explains how Plus made it big as a part of our series to celebrate Plus's tenth anniversary.