The scale of a map is 1:3000000, that is, how many kilometers is the actual distance represented by 1 cm on the map.
一幅地图的比例尺是1：3000000，即地图上1厘米表示实际距离为多少千米．
<gadget id="calculator">3_000_000 / 1 / 100_000</gadget>
<output>30</output>

<result>30</result>