The former term of a ratio is 4, when it is increased by 8, how much must the latter term be multiplied to keep the ratio constant
一个比的前项是4，当它增加8时，要使比值不变，后项必须乘以多少
<gadget id="calculator">4 + 8</gadget>
<output>12</output>

<gadget id="calculator">12 / 4</gadget>
<output>3</output>

<result>3</result>