# Man vs Maths

A review of Timothy Revell’s new book, describing the hidden mathematics behind our world

I chanced upon this book in the popular science section of an independent bookshop, and my attention was grabbed by the vivid blue of the cover, and I was further drawn in by its ‘funky’ design. Once I read the blurb, I quickly decided that the contents of the book were for me, and I bought it.

Throughout the book, Revell uses simple examples to describe mathematical concepts such as search theory, probability and game theory, and uses relatively simple examples to explain them. Revell frequently then uses the concept to prove something totally unintuitive.

In the introduction, Revell explores 52!, the number of permutations possible with a standard deck of playing cards, and illustrates the sheer vastness of this figure in an intriguing way.

Chapter one covers search theory and describes its use, and then illustrates it with the hypothetical example of a mathematician who has lost their keys, and how they should use search theory to search their thee-room flat. I found this explanation very easy to follow, and although the outcomes were counterintuitive, I was completely convinced.

Chapter six considers probability and Revell uses the example of a family where three siblings share the same birthday (the same day and month in different years), demonstrating that this is perhaps more probable than one might intuitively suspect. The chapter ends with proving the well-known (but again counterintuitive) result that there is a greater than 50% chance that a group of 23 people will contain at least two people who share a birthday.

Chapter 11 discusses networks, and looks at a constant question of the current age, ‘why do all my Facebook friends have more friends than me?’, which is apparently known as the friendship paradox (ie your friends have more friends than you do), and then describes that this is indeed likely to be true (and refers one to the mathematical proof).

Every chapter has a final section, entitled ‘Man vs {insert chapter title}’, which describes how the maths of the chapter could be used in the real world, and this leap to give a real world (eg business) application really makes the contents of the book come to life.

Overall, the book is written in an engaging way and is ideal reading for anyone with an interest in maths, or indeed the world! I would imagine that those who teach maths would find it particularly useful as it would give a range of real world examples, and probably the inspiration for many more, that they could use in their teaching to bring ‘maths to life’.

Having discovered the book by accident and being drawn in by its design, I am delighted that I found and read it, and commend it to you.

[Banner image: Wikimedia Commons user Mediajunkiesaus, CC BY-SA 4.0]

Ed is a scientific civil servant. Outside work he is an enthusiastic promoter of mathematics, he volunteers with the Mathematics Teacher Training scheme and tutors sixth form and GCSE mathematicians. Ed is a fellow of the Institute of Mathematics and its Applications and writes frequently in its ‘Mathematics Today’ magazine.

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