On a map with a scale of 1:5,000,000, the distance from Beijing to Tianjin is 30cm. What is the actual distance from Beijing to Tianjin in km?
在比例尺是1：5000000的地图上，量得北京到天津的距离30cm，北京到天津的实际距离是多少km．
<gadget id="calculator">1 / 5_000_000</gadget>
<output>1/5_000_000 = around 0</output>

<gadget id="calculator">30 / (1/5_000_000) / 100_000</gadget>
<output>1_500</output>

<result>1_500</result>