Add 6 to the numerator of (3/5), how much should be added to the denominator to keep the fraction value unchanged
把(3/5)的分子加6，要使分数值不变，分母应加多少
<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<gadget id="calculator">15 - 5</gadget>
<output>10</output>

<result>10</result>