On a map of Yunnan, the actual distance is 160 kilometers represented by a line segment of 4 cm. What is the scale of this map?
在一幅云南地图上用4厘米的线段表示实际距离160千米，这幅地图的比例尺是多少
<gadget id="calculator">160 * 100_000</gadget>
<output>16_000_000</output>

<gadget id="calculator">4 / 16_000_000</gadget>
<output>1/4_000_000 = around 0</output>

<result>1/4_000_000 = around 0</result>