
Merry Christmas, Aperi-readers. Please enjoy this pleasing algebraic manipulation, and we’ll see you when we’ve finished eating all the mince pies!
This post is part of the Aperiodical’s 2018 Aperiodvent Calendar.

Merry Christmas, Aperi-readers. Please enjoy this pleasing algebraic manipulation, and we’ll see you when we’ve finished eating all the mince pies!
This post is part of the Aperiodical’s 2018 Aperiodvent Calendar.


Friend of the site Andrew Taylor has a host of fun gadgets on his website, the Christmassiest of which has to be this Cellular Automata Snowflake Generator. It allows you to iterate two deterministic processes that model aspects of real snowflake generation, and create your own beautiful designs.
This post is part of the Aperiodical’s 2018 Aperiodvent Calendar.

For fans of outlandishly devious puzzles, the highlight of every Christmas is the RSS Quiz. No statistical knowledge is needed, but you will need all of your lateral thinking skills, extreme Google-fu and inspired leaps of pure intuition (these will form a set of what mathematicians call ‘necessary but not sufficient conditions’). You can’t win a prize if you’re not a member of the society, but since the questions are so preposterously difficult, this is unlikely to have a material effect.
Update: as RSS quizmaster Tim Paulden has pointed out in the comments, this year’s quiz has also been published by The Guardian, where there is a prize available to non-RSS-member teams.
This post is part of the Aperiodical’s 2018 Aperiodvent Calendar.
![]() |
![]() |
Are Christmas Cracker jokes not funny because they’re cleverly designed to inspire a sense of friendship through shared disappointment? Or are there just not many workable puns available with Yuletide subject matter? Either way, the one thing guaranteed to make them even unfunnier is shoehorning in some obscure mathematical concepts. So why not have a look at our post from 2012 with ten of our ‘favourites’?
This post is part of the Aperiodical’s 2018 Aperiodvent Calendar.
![]() |
![]() |
If you’re a knitter or crocheter, or just like making things, knitter and mathematician Pat Ashforth has put together a knitting pattern for cube-shaped baubles with the structure of Borromean Rings (each of the three components is linked through the others, and can’t be separated, but if any one of them is cut, the other two are unlinked). There’s a variety of ways to jazz them up, and they’re ideal for using up leftover bits of yarn, as they only need a small quantity.
The cubes can also be used to conceal a small gift. The pattern includes instructions for making the same object from paper/card, or coloured plastic folders.
This post is part of the Aperiodical’s 2018 Aperiodvent Calendar.

The National Society for the Prevention of Cruelty to Children (NSPCC) has announced 1st February 2019 as ‘Number Day 2019’, saying:
It’s maths, but not as you know it.
Join thousands of schools for a mega maths-inspired fundraising day and raise money for the NSPCC.
Whether you dedicate a day or an hour to being a maths maverick, every pound you raise counts towards our fight for every childhood.
Schools that register get digital resources to use in class, fundraising tips, maths activities, posters and safeguarding teacher resources.
Number Day 2019 at NSPCC.

Our Katie was on BBC Two last night! As part of the QI Christmas special, Katie told that old chestnut about infinitely many mathematicians walking into a bar.
Viewers in the UK can see the show on the iPlayer; Katie’s segment starts about 12 minutes in.