public function subtract(Number $subtractor)
    {
        $resultDecimalValue = $this->decimalValue() - $subtractor->decimalValue();

        $result = new Number($resultDecimalValue);

        return $result->convert($this->getNumberSystem());
    }
public function subtract(Number $subtractor)
    {
        $resultDecimalValue = $this->decimalValue() - $subtractor->decimalValue();

        $result = new Number($resultDecimalValue);

        return $result->convert($this->getNumberSystem());
    }
public function subtract ( Number $ subtractor ) { $ resultDecimalValue = $ this -> decimalValue ( ) - $ subtractor -> decimalValue ( ) ; $ result = new Number ( $ resultDecimalValue ) ; return $ result -> convert ( $ this -> getNumberSystem ( ) ) ; }
Subtract two numbers.
The number-system of the result will be the one of the number
who's was the called object.

@param Number $subtractor

@return Number
Subtract two numbers . The number - system of the result will be the one of the number who s was the called object .