Add 10 to the numerator of (2/3), how much to add to the denominator to keep the fraction size unchanged
把(2/3)的分子加上10，要使分数大小不变，分母加上多少
<gadget id="calculator">3 * 6</gadget>
<output>18</output>

<gadget id="calculator">18 - 3</gadget>
<output>15</output>

<result>15</result>