A little book on the history of the ratio of the circumference of a circle to its diameter. I memorized Pi to this level of accuracy a long while ago and haven’t forgotten it. Pi is a fascinating number that has been a heart of mathematics for several thousand years. In the Joy of PI, David Blatner prints the first million digits of pi (in small type). In and amongst these blocksof small numbers, he tells stories of pi. Mathphiles know some of these already and I already did. The earliest origins of pi, in Babylon and Egypt, the Pythagoreans, the story of how the Bible implies a value of 3, and other tales make up the book. Blatner also throws in a lot of pi trivia and facts and references to it in history and fiction and popular culture. Blatner’s format, though, is a mixed bag. With a riot of different font sizes, colors and layouts, the book is a little too quirky and noisy for my taste. This distracts, I think from reading the book at great length, even if it is short. And to get those million digits to fit in a small book of this size, most of them are of a size that can only be really read with a magnifying glass. While the book is a very slight confection of a book (and probably not really worth a purchase), it was fun to flip through. Oh, and the one millionth digit of pi? It’s a one.