3: When adding 6 to the former term of 4, the ratio of the latter term should be multiplied remains unchanged.
3：4的前项加上6，后项应乘以多少比值不变．
<gadget id="calculator">3 + 6</gadget>
<output>9</output>

<gadget id="calculator">9 / 3</gadget>
<output>3</output>

<result>3</result>