Add 14 to the numerator of (7/8), how much should be added to the denominator to keep the size of the fraction unchanged.
(7/8)的分子加上14，要使分数的大小不变，分母应加上多少．
<gadget id="calculator">7 + 14</gadget>
<output>21</output>

<gadget id="calculator">21 / 7</gadget>
<output>3</output>

<gadget id="calculator">3 * 8</gadget>
<output>24</output>

<gadget id="calculator">24 - 8</gadget>
<output>16</output>

<result>16</result>