On a map of 1:40000000, the railway line from Urumqi to Lanzhou is about 1900km long. What is the length in centimeters between the two places on the map?
在一幅1：40000000的地图上，量得乌鲁木齐到兰州的铁路线大约长1900km．地图上两地之间的长度是多少厘米？
<gadget id="calculator">1 / 4_000_000</gadget>
<output>1/4_000_000 = around 0</output>

<gadget id="calculator">(1/4_000_000) / 10</gadget>
<output>1/40_000_000 = around 0</output>

<gadget id="calculator">1_900 * 100_000 * (1/40_000_000)</gadget>
<output>19/4 = around 4.75</output>

<result>19/4 = around 4.75</result>