From Beijing to Nanjing, the distance between the two places measured on a Chinese map with a scale of 1:4500000 is 10 centimeters. What is the actual distance between Beijing and Nanjing in kilometers?
北京到南京，在比例尺是1：4500000的中国地图上量得两地之间的距离是10厘米，北京到南京两地之间的实际距离是千米？
<gadget id="calculator">1 / 4_500_000</gadget>
<output>1/4_500_000 = around 0</output>

<gadget id="calculator">10 / (1/4_500_000) / 100_000</gadget>
<output>450</output>

<result>450</result>