Popular maths is a pig to write – much harder than the rest of popular science. Unless you are dealing with one of the glamorous aspects like infinity or Fermat’s last theorem, there are two big problems in grabbing a reader’s attention. One is that the maths itself can be more than a little impenetrable, and the other is that the applications (if there are any) can seem more like mental doodling than telling us something mind blowing about reality, as is the case with something like physics. Jennifer Ouellette sets out to address both these problems in a very personal take on calculus and its importance to us. She is a self-admitted fearer of calculus, an English graduate for whom it was once all a mystery – but with help from her physicist husband, she sets out to tame this powerful mathematical tool. It’s a recipe for a really enjoyable book, and it kind of works. Ouellette takes us on a very personal journey, so there’s a lot about her and her husband and their adventure...