A rectangular green belt is 20 meters long and 15 meters wide. On a plan with a scale of 1:500, how many centimeters should the length of this green belt be drawn?
一个长方形绿化带，长20米，宽15米，在比例尺是1：500的平面图上，这条绿化带的长应该画多少厘米．
<gadget id="calculator">20 * 100</gadget>
<output>2_000</output>

<gadget id="calculator">1 / 500</gadget>
<output>1/500 = around 0.002</output>

<gadget id="calculator">2_000 * (1/500)</gadget>
<output>4</output>

<result>4</result>