Short-Cut Math
โ Gerard W. Kelly
๐ Library
๐
1984
๐ Dover Publications
๐ English
Clear, concise compendium of about 150 time-saving math short-cuts features faster, easier ways to add, subtract, multiply, and divide. Each problem includes an explanation of the method, a step-by-step solution, the short-cut solution, and proof, as well as an explanation of why it works. No specia