On a map with a scale of 1:200,000, the distance on the map is 5 cm, which represents the actual distance in kilometers.
在一幅比例尺是1：200000的地图上，图上距离是5厘米，表示实际距离是多少千米．
<gadget id="calculator">1 / 200_000</gadget>
<output>1/200_000 = around 0.000005</output>

<gadget id="calculator">5 / (1/200_000) / 100_000</gadget>
<output>10</output>

<result>10</result>