If 6 is added to the numerator of the fraction (3/5), how much should be added to the denominator to keep the size of the fraction constant?
如果给分数(3/5)的分子加上6，要使分数的大小不变，分母应加上多少
<gadget id="calculator">15 - 5</gadget>
<output>10</output>

<result>10</result>