Six Math Essentials

4 hours ago (terrytao.wordpress.com)

I'm sure it's a great book :).

I find good popular books on higher mathematics difficult to come by. A nice exception is the trilogy written by Avner Ash and Robert Groß:

Elliptic Tales, Fearless Symmetry and Summing it up (in my order of preference)

Terence Tao: Just a brief announcement that I have been working with Quanta Books to publish a short book in popular mathematics entitled “Six Math Essentials“, which will cover six of the fundamental concepts in mathematics.