Add 20 to the numerator of (5/12), how much should the denominator be multiplied to keep the size of the fraction constant?
把(5/12)的分子加上20，要使分数的大小不变，分母要乘多少
<gadget id="calculator">5 + 20</gadget>
<output>25</output>

<gadget id="calculator">25 / 5</gadget>
<output>5</output>

<result>5</result>