The numerator of (4/11) is increased by 12, how much should the denominator be increased to keep the size of the fraction constant.
(4/11)的分子增加12，要使分数的大小不变，分母应增加多少．
<gadget id="calculator">4 + 12</gadget>
<output>16</output>

<gadget id="calculator">16 / 4</gadget>
<output>4</output>

<gadget id="calculator">11 * 4</gadget>
<output>44</output>

<gadget id="calculator">44 - 11</gadget>
<output>33</output>

<result>33</result>