On a map with a scale of 1:4,000,000, the distance from Beijing to Yinchuan is 14.5cm. What is the actual distance from Beijing to Yinchuan?
在比例尺是1：4000000的地图上，量得北京到银川市的距离是14.5cm．北京到银川市的实际距离是多少km？
<gadget id="calculator">1 / 4_000_000</gadget>
<output>1/4_000_000 = around 0</output>

<gadget id="calculator">14.5 / (1/4_000_000) / 100_000</gadget>
<output>580</output>

<result>580</result>