The best thing about Christmas are the presents! So in this year's advent calendar we bring you some of our favourite books and other mathematical toys, so you can surprise your friends and family or, even better, yourself!
If you don't feel like shopping, you can win a copy of our new book Numericon: A journey through the hidden lives of numbers. All the images in our advent calendar below come from articles or news stories that have appeared on Plus over the last year. If you can identify those 24 articles, then email us the links or titles. The first person to get it right will win a copy of the book! As Christmas is sadly over, this competition is now closed. Happy new year!