public function quotient($that) : BigDecimal
    {
        $that = BigDecimal::of($that);

        if ($that->isZero()) {
            throw DivisionByZeroException::divisionByZero();
        }

        $p = $this->valueWithMinScale($that->scale);
        $q = $that->valueWithMinScale($this->scale);

        $quotient = Calculator::get()->divQ($p, $q);

        return new BigDecimal($quotient, 0);
    }