Autore: Gerard W. Kelly

Can you multiply 362 x .5 quickly in your head? Could you readily calculate the square of 41? How much is 635 divided by 2½? Can 727, 648 be evenly divided by 8? If any of these questions took y …

Clear, concise compendium of about 150 time-saving math short-cuts features faster, easier ways to add, subtract, multiply, and divide. Each problem includes an explanation of the method, a step-by-s …