After adding 40 to the denominator of (5/8), how much should be added to the numerator to keep the size of the fraction unchanged?
(5/8)的分母加上40后，要使分数的大小不变，分子应加上多少
<gadget id="calculator">40 / 8</gadget>
<output>5</output>

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

<result>25</result>