A duck weighs 4 kg, and a sheep weighs 8 times as much. How much does a sheep weigh more than a duck?
一只鸭重4千克，一只羊的重量是它的8倍．羊比鸭重多少千克？
<gadget id="calculator">4 * 8</gadget>
<output>32</output>

<gadget id="calculator">32 - 4</gadget>
<output>28</output>

<result>28</result>