Modular arithmetic,

the arithmetic of the rest - in math ematics, a system of integers, where the number of wrap up after a certain date for the modulo value set (abbreviated mod). An exa mple might be a 24-hour clock: we divide days, 24 hours numbered from 0 to 23 If now is 19:00, is 8 hours later will be 27:00 (this result would obtain by adding 19 8 = 27), but 3:00. Similarly, if now is 12:00 and it will be 21 hours, the clock indicates 9:00, not 33:00.