In this issue's teacher package we look at some of the maths and science behind a recent expedition to the Arctic. The aim of the Catlin Arctic Survey was to gather data on ice thickness that will help to predict when the North Pole sea ice cover will melt, an event that will have dramatic consequence for the Arctic ecosystem and the Earth's climate as a whole. Plus was commissioned by Catlin Arctic Survey Education to produce mathematics and science enrichment material for ages 14 to 19 (key stages 4 and 5). The toolkits look at climate and sea ice models, GPS and cartography, how to predict future climate trends, and how to present statistical evidence.

So basic, yet so tricky: prime numbers are the atoms among natural numbers and lie at the centre of some of the most difficult open problems in maths. This package brings together all material we have on primes, from prime number algorithms to new discoveries. And you will find out what all that's got to do with David Beckham.

This issue's teacher package brings together all Plus articles on group theory, exploring its applications and recent breakthroughs, and giving explicit definitions and examples of groups. It also has some handy links to related problems on our sister site NRICH.

This issue's teacher package brings together all Plus articles on vectors and matrices, exploring anything from the maths of computer movies to climate change. It also has some handy links to related problems on our sister site NRICH.