Add 4 to the numerator of (2/3), how much should the denominator be multiplied to keep the size of the fraction constant
给(2/3)的分子加上4，要使分数的大小不变，分母应该乘多少
<gadget id="calculator">4 + 2</gadget>
<output>6</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<result>3</result>