a device for calculating a result or an integer multiple of the result of a division of a numerator by a denominator includes a unit for providing a factor which is selected such that a product of the factor and the denominator is greater than the result . the device further includes a unit for modularly reducing a first product of the numerator and the factor using a modulus equaling a sum of a second product of the denominator and the factor and of an integer to obtain an auxiliary quantity having the result . a unit is used to extract the result or the integer multiple of the result from the auxiliary quantity . a division is thus reduced to a modular reduction and an extraction which is uncomplicated as far as calculation is concerned so that , in particular in long - number division tasks , the speed on the one hand and the safety on the other hand are increased .