### 7.4 Arithmetic Operators

The arithmetic operators take numeric operands and produce numeric results.

`a + b`

  Yields the sum of a and b.

`a - b`

  Subtracts b from a and yields the difference.

`a * b`

  Yields the product of a and b. If either a or b is 0, then the result is 0, even if the other operand is missing.

`a / b`

  Divides a by b and yields the quotient. If a is 0, then the result is 0, even if b is missing. If b is zero, the result is system-missing.

`a ** b`

  Yields the result of raising a to the power b. If a is negative and b is not an integer, the result is system-missing. The result of `0**0` is system-missing as well.

`- a`

  Reverses the sign of a.