Dead Reckoning: Calculating Without Instruments

I have a long relationship with this book; I saw it at Green Apple books in San Francisco when I was a kid, and I must have looked at it ten or twelve times before I bought it. In some ways, this is the story of the book itself; like a good textbook, it's not a fast read, but something you have to come back to repeatedly. Some books are smooth, fast reads; you can't put them down. These books delight because they transport you, carry you away. Other books are great for exactly the *opposite* reason. Every time you read a page, you have a new thing to think about and chew on, and you have to put the book down and think about that idea for a day or two. Dead Reckoning is one of these books. I'm delighted every time I digest a new idea/skill, and this book is packed with them.

There are many books designed to teach rapid calculation without aid of a machine. The topic that sets this one apart, and the entire reason I bought it is that it covers logarithms. Unlike most of the books in this genre this one does not waste space with endless examples and practice problems, anybody can create there own. It does back an impressive array of methods to increase speed in pencil and paper calculation, and makes it clear that each method has a time and place for maximal performance. This book was well thought out, but unfortunately not well proofread. For example, pp 14 and 15 have the following mistakes: "125 x n = 8n,000 / 8" should read "125 x n = n,000 / 8" "37 can be represented as 111/4" should read "37 can be represented as 111/3" The typos caused me to verify every method presented, but could lead unsuspecting travelers down the wrong path. BOTTOM LINE: This books is a wonderful treasury of number sense that is riddled with typos.

Imagine transforming your mind into a slide-rule with the added bonus of extra precision! "Dead Reckoning" is the ONLY book of its kind, running the gamut from ordinary operations like multiplication and division to roots (square, higher-order, and reciprocal), logarithms and their inverses, and finally trigonometric functions and their inverses. The book also contains other gems such as factorization techniques, continued fractions (for creating rational approximations), and also an algorithm which permits mental square root extractions to arbitrary precision. Those who feel daunted by symbolic formulas needn't worry, the book is replete with examples which provide both clarity and realism to the presentation. The author has an engaging style and has obviously taken great pains; the clarity of the exposition is excellent throughout. Moreover, the text is profusely referenced for those wishing to further pursue a topic that piques their interest. The techniques and strategies contained therein are as practical as they are efficient and are equally amenable to quick pen-and-paper calculations for those not interested in pursuing mental computations. Heartily recommended! - Grant Nixon