Python supports all the arithmetic you'd expect, plus a couple of operators unique to programming languages.

| Operator | Meaning | Example | Result | | --- | --- | --- | --- | | + | Addition | 5 + 2 | 7 | | - | Subtraction | 5 - 2 | 3 | | * | Multiplication | 5 * 2 | 10 | | / | Division (always returns a float) | 5 / 2 | 2.5 | | // | Floor division (rounds down to an int) | 5 // 2 | 2 | | % | Modulo (remainder) | 5 % 2 | 1 | | ** | Exponent (power) | 5 ** 2 | 25 |

print(5 + 2)
print(5 / 2)
print(5 // 2)
print(5 % 2)
print(5 ** 2)

Floor division vs. regular division

/ always gives you a float, even when the numbers divide evenly. // rounds the result down to the nearest whole number. This distinction matters a lot once you start working with things like pagination or splitting items into groups.

print(10 / 3)
print(10 // 3)

Modulo — a surprisingly useful operator

% gives you the remainder of a division. It's the standard way to check things like "is this number even?" (an even number has a remainder of 0 when divided by 2).

print(7 % 2)
print(8 % 2)

Operator precedence

Just like in math class, Python evaluates some operators before others. ** runs first, then *, /, //, % (left to right), then + and - (left to right). Parentheses () always run first and can be used to force a specific order.

print(2 + 3 * 4)
print((2 + 3) * 4)
print(2 ** 3 + 1)

Try it yourself

Given the numbers 17 and 5, print the result of dividing them with /, //, and %.

Checkpoint

• / always returns a float; // floors to an int; % gives the remainder.
• ** is exponentiation.
• Precedence: parentheses, then **, then * / // %, then + -.