The distance from Binhai to Nanjing is 800 kilometers, and the distance between them is 5 centimeters measured on a map. The distance from Nanjing to Shanghai is measured as 2 cm on this map, so what is the approximate actual distance from Nanjing to Shanghai?
从滨海到南京的距离为800千米，在一幅地图上量得它们之间的距离为5厘米．在这幅地图上量得南京到上海的距离为2厘米，那么南京到上海的实际距离大约是多少？
<gadget id="calculator">800 / 5</gadget>
<output>160</output>

<gadget id="calculator">160 * 2</gadget>
<output>320</output>

<result>320</result>