protected function divideScalar($scalar) : self
    {
        if (!is_int($scalar) and !is_float($scalar)) {
            throw new InvalidArgumentException('Scalar must be an integer'
                . ' or float, ' . gettype($scalar) . ' found.');
        }

        $b = [];

        foreach ($this->a as $row) {
            $temp = [];

            foreach ($row as $value) {
                $temp[] = $value / $scalar;
            }

            $b[] = $temp;
        }

        return self::quick($b);
    }