Faster Arithmetic for Adults

Looking for a serious book on how arithmetic works and how to improve your skills? Faster Arithmetic, a book for adults who already know the basics of arithmetic, is packed with examples and explanations that enable you to discover more than 150 techniques to speed up your arithmetic and increase your understanding of numbers. Faster Arithmetic contains information from the days before calculators, from Newton (and before) through the nineteenth century. Learn efficient way to improve your ability to add, subtract, find powers and roots -- and more -- with explanations involving no more than simple algebra (usually), and even contains an easy way to compute pi from basic principles!