The maths of growth is one of the many topics explored on STEM NRICH.

Want to stop your brain from rusting this Christmas? Then visit our sister project NRICH which received a major make-over this year and now has a beautiful new website. NRICH is aimed at students and teachers of maths of all ages and backgrounds. It offers challenging and engaging activities that develop mathematical thinking and problem-solving skills and show rich mathematics in meaningful contexts.

To train your brain have a look at the NRICH advent calendar, which has an activity for every day up to Christmas, or the regular weekly challenge. If you're interested in real-life applications of maths, then visit STEM NRICH which explores the ways in which mathematics, science and technology are linked. And if you're stuck on a problem or have a general maths question you can ask the team at the Ask NRICH forum.

Because life is too short for long division!