Add 10 to the numerator of (5/7), what should be the denominator to keep the fraction value unchanged
(5/7)的分子加上10，要使分数值不变，分母应多少
<gadget id="calculator">10 + 5</gadget>
<output>15</output>

<gadget id="calculator">15 / 5</gadget>
<output>3</output>

<result>3</result>