Do high-speed, complicated arithmetic in your head using the Trachtenberg Speed System.Ever find yourself struggling to check a bill or a payslip? With The Trachtenberg Speed System you can. Described as the ''shorthand of mathematics'', the Trachtenberg system only requires the ability to count from one to eleven. Using a series of simplified keys it allows anyone to master calculations, giving greater speed, ease in handling numbers and increased accuracy.Jakow Trachtenberg believed that everyone is born with phenomenal abilities to calculate. He devised a set of rules that allows every child to make multiplication, division, addition, subtraction and square-root calculations with unerring accuracy and at remarkable speed. It is the perfect way to gain confidence with numbers.