Do the Math - the way your grandmother did. A simple step-by-step guide to doing arithmetic the way it was taught 50 years ago when American high school graduates led the world in math and science. High school graduates, even those who were not college- bound, knew how to count back change or work with fractions and decimals in measuring and calculating necessary materials for construction, manufacturing, decorating, sewing, etc, and balance a checkbook. ( ) The key is keeping it simple. This method worked then, and it still works today.