How to Calculate Quickly: Full Course in Speed Arithmetic

Do you want to double or triple the speed with which you calculate? How to Calculate Quickly is a tried and true method for helping you in the mathematics of daily life — addition, subtraction, multiplication, division, and fractions.
The author can awaken for you a faculty which is surprisingly dormant in accountants, engineers, scientists, businesspeople, and others who work with figures. This is "number sense" — or the ability to recognize relations between numbers considered as whole qu...