Subtract the same number from the denominator and numerator of (19/27) to get (5/9). What is the subtracted number?
将(19/27)的分母和分子减去同一个数后得(5/9)，减去的这个数是多少．
<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">(5/9) * 27</gadget>
<output>15</output>

<gadget id="calculator">19 - 15</gadget>
<output>4</output>

<gadget id="calculator">1 - (5/9)</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">4 / (4/9)</gadget>
<output>9</output>

<result>9</result>