A city needs to build a green belt on both sides of the main road in the urban area, each green belt is 5 meters wide and 4000 meters long. So, how many hectares do these two green belts occupy?
一座城市要在城区主干道两侧各修建一条绿化带，每条绿化带宽5米，长4000米．那么，这两条绿化带占地多少公顷？
<gadget id="calculator">5 / 10_000</gadget>
<output>1/2_000 = around 0.0005</output>

<gadget id="calculator">4_000 * (1/2_000) * 4_000 * (1/2_000)</gadget>
<output>4</output>

<result>4</result>