Add 10 to the numerator of (2/9), how much should be added to the denominator to keep the size of the fraction unchanged.
(2/9)的分子加10，要使分数的大小不变，分母应加多少．
<gadget id="calculator">9 * 6</gadget>
<output>54</output>

<gadget id="calculator">54 - 9</gadget>
<output>45</output>

<result>45</result>