Subtitled 'overlooked and omitted topics in mathematics', the obvious concern is that there is a good reason these topics are overlooked and omitted. Thankfully, this is not the case, but it's fair to say that despite attempts to dress it up that way, this isn't a recreational maths book. There's a fair description in the blurb: 'the topics which every undergraduate mathematics student "should" know, but has probably never encountered... magnificent secrets that are beautiful, useful and accessible.' As someone who many years ago did a degree with a fair amount of mathematics in it, I think it probably would have appealed back then - though to be honest a lot of it has disappeared from my memory, strongly reducing the entertainment value. Here's an example. The first real page contains the sentence:  'If you are handed a real number 𝓍 ∈  ⁠ ⁠,  one way to tell if 𝓍 is rational or irrational is to look at sequences of rational numbers q n ...