On a map with a scale of 1:5,000,000, the length of the expressway from Yimen to Kunming is measured as 2 cm. What is the actual length of the expressway from Yimen to Kunming in kilometers?
在一幅比例尺为1：5000000的地图上，量得易门到昆明的高速公路长为2厘米，易门到昆明的高速公路实际长是多少千米．
<gadget id="calculator">1 / 5_000_000</gadget>
<output>1/5_000_000 = around 0</output>

<gadget id="calculator">2 / (1/5_000_000) / 100_000</gadget>
<output>100</output>

<result>100</result>