The chances are, dear Aperiodical reader, that you’re familiar with the following chain of emotions while browsing Facebook:

• Oo! A notification!
• Oo! A message from Aunty Jean, I’ve not heard from them in ages!
• Oh. It’s one of those.

I don’t even need to tell you what “one of those” means, do I? It likely has a picture of Einstein. It probably makes a spurious claim about the percentage of people who will fail. I’d make a small bet that it involves the abuse of at least one mathematical symbol.

And, inexplicably, it’ll have thousands of comments stating their answer, generally with a sardonic comment about how those with a differing opinion are fools who should have paid more attention at school.

So, you can imagine the utter delight with which I learned that mathematical comedy singer-songwriter Kyle D Evans had written a book devoted to the viral maths problems that are the bane of any right-thinking person’s existence.

It turns out, a maths teacher with a background in comedy is pretty much the perfect person to write such a book. Evans picks a variety of viral problems, from the obvious dubious obelus we all know and loathe to the far more edifying geometry problems of Catriona Agg, and the borderline useful fact that \(x\)% of \(y\) is the same as \(y\)% of \(x\), and he handles them with exactly the attitude they merit: deserved snark, childish curiosity and a sort of “hey! that’s neat! Here’s why it works!” attitude I hope I’d be able to bust out in the pub if someone asked about it.

I’d have liked to see a bit more about the psychology of what makes a mathematical nugget go viral (Evans sort of shrugs his shoulders a bit about this: sometimes things get lots of attention and sometimes they don’t), but this is a very minor quibble about an excellent book. (I’m also disappointed that the phrase “write the bloody thing properly,” the canonical correct answer to annoying Facebook problems, does not appear.)

It’s a book you, a mathematician, can enjoy by reading it; you can also enjoy it by sending it to your Aunty Jean with a note saying “this will explain it.” Aunty Jean is notoriously difficult to buy Christmas presents for. Now you’re sorted.

Maths Tricks To Blow Your Mind, A Journey Through Viral Maths by Kyle D Evans is published by Atlantic Books, £9.99 in hardback, out October 7th 2021.

Colin received a free review copy of the book.