Steven Strogatz: The Joy of x: A Guided Tour of Math, from One to Infinity.
Wed, Jan 25, 2017./noise/books | LinkKindle. This is a compilation of his columns in the New York Times from a few years back. There are some hits, some misses, and almost all could do with expansion; the notes make up for this somewhat. Strogatz wisely defers to others for depth and I have quite a few pointers to chase now. I guess that was his intention.