Dongdong's family is in Beijing, and his grandma's is in Nanjing. He measured the length of the railway line from Beijing to Nanjing on a map with a scale of 1:6,000,000, which is about 15 centimeters, and the actual distance from Beijing to Nanjing is in kilometers.
东东家在北京，奶奶家在南京，他在比例尺是1：6000000的地图上量得北京到南京的铁路线长约为15厘米，北京到南京的实际距离为多少千米．
<gadget id="calculator">1 / 6_000_000</gadget>
<output>1/6_000_000 = around 0</output>

<gadget id="calculator">15 / (1/6_000_000) / 100_000</gadget>
<output>900</output>

<result>900</result>