On a drawing with a scale of 1:2000, the side length of a square piece of land is measured as 4 cm. What is the actual area of this square piece of land in square meters?
在比例尺是1：2000的图纸上，量得一块正方形土地的边长是4厘米，这块正方形土地的实际面积是多少平方米？
<gadget id="calculator">1 / 2_000</gadget>
<output>1/2_000 = around 0.0005</output>

<gadget id="calculator">4 / (1/2_000) / 100</gadget>
<output>80</output>

<gadget id="calculator">80 * 80</gadget>
<output>6_400</output>

<result>6_400</result>