Uncle Liu planted fruit trees on a rectangular piece of land 800 meters long and 50 meters wide. How many hectares does this land cover?
刘大伯在一块长800米，宽50米长方形土地上种果树．这块土地的占地面积是多少公顷？
<gadget id="calculator">800 * 50</gadget>
<output>40_000</output>

<gadget id="calculator">40_000 / 10_000</gadget>
<output>4</output>

<result>4</result>