A rectangular piece of land has an area of 2 hectares, its length is 400 meters, and its width is in meters.
一块长方形地的面积是2公顷，它的长是400米，宽是多少米．
<gadget id="calculator">2 * 10_000</gadget>
<output>20_000</output>

<gadget id="calculator">20_000 / 400</gadget>
<output>50</output>

<result>50</result>