On a drawing with a scale of 1:400, measure a rectangular piece of land with a length of 8 cm and a width of 5 cm. What is the actual area of the land in square meters?
在比例尺是1：400的图纸上，测得一块长方形地的长为8厘米、宽为5厘米．这块地的实际面积是多少平方米？
<gadget id="calculator">1 / 400</gadget>
<output>1/400 = around 0.0025</output>

<gadget id="calculator">8 / (1/400) / 100</gadget>
<output>32</output>

<gadget id="calculator">5 / (1/400) / 100</gadget>
<output>20</output>

<gadget id="calculator">32 * 20</gadget>
<output>640</output>

<result>640</result>