The denominator of (2/(A))(A is not equal to 0) is multiplied by 3, how much should be added to the numerator to keep the fraction size unchanged
(2/(A))(A不等于0)的分母乘以3，要使分数大小不变，分子应加多少
<gadget id="calculator">2 * 3</gadget>
<output>6</output>

<gadget id="calculator">6 - 2</gadget>
<output>4</output>

<result>4</result>