The numerator of (2/11) increases by 4, how much should the denominator increase to keep the size of the fraction constant.
(2/11)的分子增加4，要使分数的大小不变，分母应该增加多少．
<gadget id="calculator">11 * 3</gadget>
<output>33</output>

<gadget id="calculator">33 - 11</gadget>
<output>22</output>

<result>22</result>