Integer Division

Regular division gives you decimals: $7 \div 3 = 2.333...$. But integer division throws away the decimal part and keeps only the whole number: $7 \div 3 = 2$.

In most languages, if both operands are integers, division is integer division. Python uses $//$ for explicit integer division. C++ and Java do it automatically when both operands are int types.

This comes up constantly. If you have $n$ items and want to split them into groups of $k$, the number of full groups is $\lfloor n / k \rfloor$.