The numerator of (3/8) is multiplied by 3, how much should be added to the denominator to keep the size of the fraction unchanged.
(3/8)的分子乘3，要使分数的大小不变，分母应该加上多少．
<gadget id="calculator">24 - 8</gadget>
<output>16</output>

<result>16</result>