2: The latter term of 3 is increased by 3, how much should the former term be increased to keep the ratio constant
2：3的后项增加3，要使比值不变，前项应增加多少
<gadget id="calculator">3 + 3</gadget>
<output>6</output>

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

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

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

<result>2</result>