2 dogs weigh the same as 6 rabbits, 1 rabbit weighs the same as 3 ducks, and 1 dog weighs the same as how many ducks.
2只狗与6只兔同样重，1只兔和3只鸭同样重，1只狗和多少只鸭同样重．
<gadget id="calculator">6 / 2</gadget>
<output>3</output>

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

<result>9</result>