The weight of 2 sheep = the weight of 1 pig, the weight of 4 pigs = the weight of 1 cow, so the weight of 2 cows = the weight of how many sheep.
2只羊重量=1头猪重量，4头猪重量=1头牛重量，所以2头牛重量=多少只羊重量．
<gadget id="calculator">2 * 4</gadget>
<output>8</output>

<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<result>16</result>