If you add 9 to the former term of 3:8, how much should you add to the latter term to keep its ratio unchanged?
如果把3：8的前项加上9，要使它的比值不变，后项加上多少
<gadget id="calculator">8 * 4</gadget>
<output>32</output>

<gadget id="calculator">32 - 8</gadget>
<output>24</output>

<result>24</result>