The Number Mysteries: A Mathematical Odyssey Through Everyday Life [Hardcover]

I have previously read and reviewed Rob Eastaway's books Why Do Buses Come in Threes? and How Long Is a Piece of String? on The hidden mathematics of everyday life, but although I've been aware of Marcus Du Sautoy's books for some time, this is the first I've actually bought and read. While his approach is different from Rob's, Marcus also has a way of explaining mathematics such that it can appeal to the wider public. The book is divided into five chapters, the basic themes being prime numbers, geometric shapes, winning streaks, coded information and predicting the future.

Perhaps the most amusing subject in the first chapter is the life-cycle of cicadas, which are apparently 7, 13 or 17 years in duration, depending on the species. The author suggests this cycle using one of three prime numbers may be a way of discouraging predators, but as he`s a mathematician rather than a biologist, I won`t assume that although it sounds plausible.

Sometimes the author strays from the chapter heading but that's no problem. For example, the first chapter discusses Fibonacci numbers (and the inevitable example of breeding rabbits) as well as prime numbers. Another off-topic digression that I found interesting was the author's discussion of the early number systems developed by ancient civilizations.

The chapter on geometric shapes is another fascinating chapter, discussing the shapes of footballs, teabags, snowflakes, coastlines, viruses and abstract paintings among other things. Golf balls aren't featured here; they come later in the book. The chapter on winning streaks discusses a variety of games and puzzles including the 18th century Königsberg bridge puzzle. Rob Eastaway also covered this puzzle in one of his books; it seems to be regarded as a particularly significant example in the world of mathematics. Marcus tells us how Königsberg has changed including the bridges.

The chapter on coded information explains that some codes appear to be uncrackable because they use very large prime numbers as multipliers, but also discusses other codes. The designers of the German Enigma code thought it was uncrackable, but British mathematicians eventually proved them wrong. There are other codes that were never meant to be secret, including the Morse code invented in the nineteenth century. The author also discusses check digits, using the ISBN book cataloguing system as an example. The last chapter on predicting the future discusses pendulums, boomerangs and weather among other things.

This is a very entertaining book although it does get a little technical here and there. As such, anybody who is in the least bit intimidated by mathematics might be better to begin with one of Rob Eastaway's books. However, I like both authors in different ways and I may end up buying more books by both authors.

It's a bit hard to review this book without having in mind Alex's Adventures in Numberland, published in the same year. Both books cover similar ground, although the approaches differ greatly. Whereas Alex Bellos travelled and spoke to various people who had a particular passion for certain aspects of mathematics or numbers, du Sautoy's book has the distinct feeling to it that he just sat down and wrote most of it straight out of what was in his own head. The ending of the book somewhat confirms this, as he states the book came out of his giving the Royal Institution Christmas lectures in 2006, and a few other projects he had previously worked on.

The book is broken down very simply into just 5 chapters, each with a basic premise to be looked at. But here, du Sautoy's passion for mathematics breaks through and he veers wildly off course and looks down a few sidestreets along the way. So if you pick a point about three-quarters of the way through each chapter, whatever is being discussed may not seem to have an immediate connection to what the chapter started out talking about. But this is not a criticism; merely a point of observation. It may not be to some people's liking, though I think it adds to the charm of the book.

Consistent with the philosophy of most mathematicians, du Sautoy believes that the joy in maths is to be found in doing it for oneself, not merely in the exposition of another. To this end, there are consistent puzzles inserted throughout the book for the reader to follow up on. So the fact that it doesn't take long to read cover to cover (I did it in 4 days) belies the depth of material that the pages didn't have room for and are followed up online. The book does get gradually more and more technical, which may put off some readers. Towards the end, I had to pull out a pen and some paper to follow a few of the steps.

Overall, it's written in a really down-to-earth manner with du Sautoy's enthusiasm evident on almost every single page, especially those page numbers which are prime numbers which he conveniently instructed the printers to make bold! I would recommend this for anyone interested in mathematics, though I disagree with the age ranged suggested (1-101, even if he did mean it in binary!). I think it should fairly accessible to an average 10 year old or a smart 8 year old, but with plenty to interest adult readers as well.

My husband has been going to bed early to "read my maths book" since my mother-in-law bought The Number Mysteries for his birthday. And he's been passing on some of the most fascinating little factoids to the seven-year-old: bubbles are lazy; the Babylonians counted in 60s on their fingers; the best footballers have prime numbers on their backs. Turns out maths is fun - who knew?