Like its sister title Science 1001 , this book takes on an enormous task: telling us ‘everything we need to know about mathematics in 1001 bite-sized explanations’. It’s a handsome, if rather heavy book, somewhere between a typical hardback and a small coffee table book in size (though with floppy covers). Inside, it’s divided into 10 main sections – from the obvious ones like geometry and algebra, through to the exotics from statistics to game theory. Each section is split into topics – so in geometry you might get ‘Euclidian geometry’ and within each topic there may be around 12 entries. In a sense, then, this is a mini-encyclopaedia of maths, though arranged by subject, rather than alphabetically. I had mixed feelings about the science entry in the series and those feelings are more extravagantly mixed than ever here. There is no doubt whatsoever that this is a useful book. A good marker of this is that, unlike many of the books that come into the review pile, I intend to keep