The numerator of (3/10) has been enlarged by 5 times, how much should be added to the denominator to keep the size of the fraction constant
(3/10)的分子扩大了5倍，要使分数的大小不变，分母应该加上多少
<gadget id="calculator">10 * 5</gadget>
<output>50</output>

<gadget id="calculator">50 - 10</gadget>
<output>40</output>

<result>40</result>