This was recommended for me to my parents a few years ago, and it's one of those books that has taken some time to getting around to. It's not that the subject matter is uninteresting, it's just that it always seems to appear when I'm looking for some variety away from scientific topics.
People often get 'mathematics' confused with 'arithmetic'; Paulos repeatedly shows that there is far more to his subject, and bemoans learning by rote - his comparison of how we study mathematics versus language and literature is elegant. As the book's subtitle suggests, the entries are arranged alphabetically by subject, which isn't an obvious choice for an essay collection, but for the most part it seems to work quite well. Some topics are placed at a very basic level and were a little tedious for me, but even these often have some insight. The more advanced topics - and there is quite a range through the book, from simple things like multiplication and basic algebra through to infinite sets, differential equations and the Turing test, with detours into Fermat, Gödel, Humour in Mathematics and Zeno - are also well written and shouldn't be beyond the range of a reasonably intelligent person even if their mathematical training is more basic, provided they have curiosity and recourse to logic and reason.