Add 16 to the denominator of (3/8), how much should the numerator be increased to keep the size of the fraction constant?
(3/8)的分母加上16，要使分数的大小不变，分子应增加多少？
<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">9 - 3</gadget>
<output>6</output>

<result>6</result>