Mathematical stunts for quick account

Forget about the calculator, this book will teach you high -speed calculations in your mind or with a pencil. To count faster, it is enough to think a little differently, her author Ingve Vogt is sure - the Norwegian journalist of the scientific journal Apollon and the fan of mathematics. You will learn about simple and boring methods of fast account, for which only knowledge of basic arithmetic rules will be needed. The Trakhtenberg method, the Chinese method of account using dashes and many other mathematical techniques will help you easily add and subtract, multiply and divide, extract a square root and build large numbers in a square.

And you will also find unusual facts and fascinating stories about the numbers and people who are crazy about them, and get acquainted with the brief millennium history of system systems, from the time of ancient Greece to today"s digital era