Short-Cut Mathematics (Kelly G. W.)(Paperback) - diskuze

Can you multiply 362 x .5 quickly in your head? Could you readily calculate the square of 41? How much is 635 divided by 21/2? Can 727,648 be evenly divided by 8?
If any of these questions took you more than a few seconds to solve, you need this book. Short-Cut Math is a concise, remarkably clear compendium of about 150 math short-cuts -- timesaving tricks that provide faster, easier ways to add, subtract, multiply, and divide.
By using the simple foolproof methods in this volume, you can double or triple your calculation speed -- even if you always hated math in school. Here's a sampling of the amazingly effective techniques you will learn in minutes: Adding by 10 Groups; No-Carry Addition; Subtraction Without Borrowing; Multiplying by Aliquot Parts; Test for Divisibility by Odd and Even Numbers; Simplifying Dividends and Divisors; Fastest Way to Add or Subtract Any
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