Add 15 to the numerator of (5/8), how much should be added to the denominator to keep the size of the fraction unchanged.
将(5/8)的分子加上15，要使分数的大小不变，分母应该加上多少．
<gadget id="calculator">8 * 4</gadget>
<output>32</output>

<gadget id="calculator">32 - 8</gadget>
<output>24</output>

<result>24</result>