Arthur Benjamin's book, Secrets of Mental Math (discussed here and here), has now been released!

As mentioned before, this is a reprint of Mathemagics: How to Look Like a Genius Without Really Trying. There are a few changes for the new edition. In addition to the original foreword by James Randi, there is a new additional foreword by Bill Nye, the Science Guy.

There are also two new chapters, "Chapter 0" and "Chapter Infinity". Chapter 0 introduces some quick math tricks with which to amaze your friends, and saves the explanations for later in the book. Co-author Michael Shermer writes Chapter Infinity, which is an epilouge called How Math Helps Us Think About Weird Things.

The remainder of the book itself remains the same. For those not familiar with the original book, it discusses faster an easier methods for mental arithmetic, including estimation, and using memory technique for working with numbers. The book then concludes with some mathematical magic tricks. There are plenty of practice exercises along the way, with the answers available in the back of the book.

As you read through the chapters, you occasionally run across side articles talking about interesting people and topics in the history of recreational mathematics. The topics of the side articles are Carl Friedrich Gauss, Zerah Colburn, the Monty Hall Problem, George Parker Bidder, Évariste Galois, Shakuntala Devi, Alexander Craig Aitken and Thomas Fuller.

Secrets of Mental Math also makes an excellent companion to Dr. Benjamin's Mathemagics video, especially as they cover many of the same areas. The book, of course, goes further in depth than can the video.

Even if you have the original, the new additions make the book worth purchasing again. If you don't have the original and are interested in improving the mental math skills of yourself or your loved ones, then I would consider this book a must-buy!