How can I calculate divide and modulo for integers in C#?

There is also Math.DivRem

quotient = Math.DivRem(dividend, divisor, out remainder);

Here's an answer from the MSDN documentation.

When you divide two integers, the result is always an integer. For example, the result of 7 / 3 is 2. To determine the remainder of 7 / 3, use the remainder operator (%).

int a = 5;
int b = 3;

int div = a / b; //quotient is 1
int mod = a % b; //remainder is 2