The length of the railway line between A and B is about 1600km. On a map with a scale of 1:40000000, what is its length in centimeters?
A、B两地的铁路线长约1600km，在一幅比例尺是1：40000000的地图上，它的长是多少厘米？
<gadget id="calculator">1 / 40_000_000</gadget>
<output>1/40_000_000 = around 0</output>

<gadget id="calculator">1_600 * 100_000 * (1/40_000_000)</gadget>
<output>4</output>

<result>4</result>