TYPO3 Core

    /**
     * @param integer|float $left
     * @param string $operator
     * @param integer|float $right
     * @return integer|float
     */
    protected static function evaluateOperation($left, $operator, $right)
    {
        if ($operator === '%') {
            return (float)$left % (float)$right;
        } elseif ($operator === '-') {
            return (float)$left - (float)$right;
        } elseif ($operator === '+') {
            return (float)$left + (float)$right;
        } elseif ($operator === '*') {
            return (float)$left * (float)$right;
        } elseif ($operator === '/') {
            return (integer) $right !== 0 ? (float)$left / (float)$right : 0;
        } elseif ($operator === '^') {
            return pow((float)$left, (float)$right);
        }
        return 0;
    }