How to Calculate Quickly

Rating:
Summary: I have kept my copy for years
Review: and keep going back to it. It is important that a prospective buyer knows this book focuses on MENTAL arithmetic, i.e., no paper. If that is an interest of yours, then this is your book. If you are interested in "shortcuts", there are other books out there (though the last chapter of this book contains some of the more popular ones.) Don't think you can multiply two two-digit numbers in your head? you may be surprised.

Rating:
Summary: Rote, rote, rote
Review: Being fairly proficient in "mental math", I picked up this book to see if there were any useful techniques for calculating. I was very disappointed.

The author's approach seems to rely primarily on rote memorization and optimizing pencil & paper methods. This is fine if you have pencil & paper handy, but cumbersome if you want to "run a rapid mental check..." as they suggest in their book. Rather than provide new techniques that work for mental computation, the reader is asked to perform endless drills to allow you to mentally perform pen & paper methods.

Another problem is the reliance on memorizing special cases instead of focusing on general-use techniques. If it takes a person 10 seconds to determine which of the dozens of special cases applies to a particular problem, then he does not know "how to calculate quickly"

For example, one of the author's special cases, "Multiplying a Sum by a Difference," actually has a very broad use for multiplying any two integers, but it is presented only briefly as a very narrow application that you will likely never stumble across in real life (e.g. multiplying two integers whose units add to 10 and the tens have a difference of 1)

Overall, the heavy reliance on rote vs. technique makes this an unsatisfying work.

Rating:
Summary: EXCELLENT BOOK TO IMPROVE MENTAL CALCULATION
Review: I gave it a five star simply because the books is simple and very effective at getting you to learn the "art" of quick calculation.

I looked at all the others in that field. Most of them teach you tricks for quick calculation. To do certain calculation you need to remember the tricks. There are dozen of them and you just get confused. This book do not used trick but teach you "number sense" ... and how to calculate from left to right with complex number. Beleive me, I was affraid of that kind of calculation and with that book I learned a lot!

I used it because I am preparing for interviews in management consulting. Case study need you to do lots of quick mental calculation. I am very good with complex calculation but mental arithmetics is something else.

BUY THIS BOOK ... very slim, but as said before, lots lots of exercise well made and improving in difficulty ... cant say more, its the book I was looking for.

Amusing, it was first published in 1945 ...

Rating:
Summary: It does what it says...
Review: Long collection of exercises to improve your mental calculating ability. This book will keep you busy for quite a while. It's slim but there's a lot of exercises in it. It will give you eough familiarity with numbers to do fairly large multiplication and division (let alone addition and subtraction) in your head. Fractions included. Requires no advanced math skills of any sort. Presupposes a knowledge of basic caluculation, that's it. No algebra, geometry etc.