the modulo operation is different from the remainder operation. "module" is the transliteration of "mod", and modular arithmetic is mostly used in programming. mod means to seek remainder. modular arithmetic is widely used in number theory and programming. from the identification of odd and even numbers to the identification of prime numbers, from modular exponentiation to the finding of the greatest common divisor, from sun tzu's problem to the caesar cipher problem, modular arithmetic is everywhere. . although many number theory textbooks have some introduction to modular arithmetic, most of them are purely theoretical and do not cover much about the application of modular arithmetic in programming.

for example 11 mod 2, value is 1

the above modular operations are mostly used in program writing. here is an example to illustrate the principle of modular operations:

turbo pascal's explanation of the mod is this:

a mod b=a-(a div b) * b (div means integer division)