A rectangular nursery is 400 meters long and 4 times its width. How many square meters does this nursery occupy?
一个长方形苗圃，长400米，是宽的4倍，这个苗圃占地多少平方米？
<gadget id="calculator">400 / 4</gadget>
<output>100</output>

<gadget id="calculator">400 * 100</gadget>
<output>40_000</output>

<result>40_000</result>