The Trachtenberg Speed System of Basic Mathematics

add half add the neighbor adding algebra arithmetic calculation chapter check-figure conventional correct course diagram divide division divisor column easy elevens-remainder equation error example find the digit-sum Find the square four-digit number Fourth step given number gives half the neighbor happens inside pair instance last digit last figure last step left-hand digit left-hand figure long number mathematics mental metic minus multi multiplicand multiplication tables multiply any number nines-remainders Notice NT product number is odd pair of digits pair-product parentheses partial dividend practice problem product rule quotient reduce remember result right answer right-hand digit right-hand figure running totals Second step simple single digit single figure square root subtract take half tens-digit Third step tick tion Trachtenberg method Trachtenberg system two-digit multipliers two-digit numbers two-figure number underlined figures units-and-tens units-digit wish to multiply working-figure write written zero in front