3 pigs can be exchanged for 9 sheep, 2 sheep can be exchanged for 6 chickens, and 1 pig can be exchanged for how many chickens.
3头猪能换9只羊，2只羊能换6只鸡，1头猪能换多少只鸡．
<gadget id="calculator">6 / 2</gadget>
<output>3</output>

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

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

<result>9</result>