Arithmetricks: 50 Easy Ways to Add, Subtract, Multiply, and Divide Without a Calculator Paperback – June 23, 1995

Arithmetricks: 50 Easy Ways to Add, Subtract, Multiply, and Divide Without a Calculator

Rapid Math Tricks & Tips: 30 Days to Number Power

Secrets of Mental Math: The Mathemagician's Guide to Lightning Calculation and Amazing Math Tricks