Suggested Readings: Short-Cut Math

Gerard W. Kelly — Short-Cut Math — Dover, 1984, 112 pp. ISBN 978-0-486-24611-6

(Buy at Amazon.com)

This little book—not even 120 pages—will help you sharpen your mental math skills using a series of tricks, strategems, and special cases that will get you to the exact result, or at least to an accurate approximation, with greater speed. The book is not exactly mind-shattering either; still, it may be useful to learn a few new tricks.