Just finished Here's Looking at Euclid by Alex Bellos; an excellent non-fiction on the history of mathematics. Interesting and thought provoking. He covers all aspects of math and its history. For example, I learned from this book that the Arabic number system we use isn't Arabic at all but rather Indian that simply spread to Arabia. Europeans discovered it during the Crusades and assumed it had originated there.
He also covers how people have used math to beat the odds in casinos. And how Suduku got started.