We don't normally review childrens' books on Plus, but when this colourful volume landed on our desk we couldn't resist. It appeared to do exactly what we try to do all the time: reveal the beauty and fun side of maths and show how it comes up everywhere, as a natural language in which to talk about the world. So we passed it on to two expert representatives of the book's target audience, which is 7 to 11-year olds.