Add 5 to the numerator of (5/8), how much should be added to the denominator to keep the size of the fraction unchanged.
(5/8)的分子加上5，要使分数的大小不变，分母应加上多少．
<gadget id="calculator">5 + 5</gadget>
<output>10</output>

<gadget id="calculator">10 / 5</gadget>
<output>2</output>

<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<gadget id="calculator">16 - 8</gadget>
<output>8</output>

<result>8</result>