On a design drawing with a scale of 1:100, the side length of a square building is measured to be 20 cm. What is the actual floor area of this building in square meters?
在一张比例尺是1：100的设计图上，量得正方形建筑物的边长是20厘米．这个建筑物的实际占地面积是多少平方米？
<gadget id="calculator">1 / 200</gadget>
<output>1/200 = around 0.005</output>

<gadget id="calculator">20 / (1/200) / 100</gadget>
<output>40</output>

<gadget id="calculator">40 * 40</gadget>
<output>1_600</output>

<result>1_600</result>