If 6 is added to the denominator of (2/3), to keep the size of the fraction unchanged, how much should the numerator be added
如果(2/3)的分母加6，要使分数的大小不变，那么分子应加多少
<gadget id="calculator">6 / 3</gadget>
<output>2</output>

<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<result>4</result>