On a map with a scale of 1:400000, if the distance between A and B is 2.5 cm, what is the actual distance in kilometers between A and B?
在比例尺是1：400000的地图上，量得A、B两地的距离是2.5厘米，则A、B两地的实际距离是多少千米．
<gadget id="calculator">2.5 / 100_000</gadget>
<output>0.000025</output>

<gadget id="calculator">400_000 * 0.000025</gadget>
<output>10</output>

<result>10</result>