Remember basic arithmetic from school? These work just like those.
Table 15-2. Arithmetic Operators
| Example | Name | Result |
|---|---|---|
| -$a | Negation | Opposite of $a. |
| $a + $b | Addition | Sum of $a and $b. |
| $a - $b | Subtraction | Difference of $a and $b. |
| $a * $b | Multiplication | Product of $a and $b. |
| $a / $b | Division | Quotient of $a and $b. |
| $a % $b | Modulus | Remainder of $a divided by $b. |
The division operator ("/") returns a float value anytime, even if the two operands are integers (or strings that get converted to integers).
Note: Remainder $a % $b is negative for negative $a.
See also the manual page on Math functions.