On a map with a scale of 1:1000 kilometers, the distance between the two places is 4.5 cm. What is the actual distance in kilometers between the two places?
在比例尺是1：1000千米的地图上量得两地的距离是4.5厘米，两地的实际距离是多少千米．
<gadget id="calculator">1 / 100_000_000</gadget>
<output>1/100_000_000 = around 0</output>

<gadget id="calculator">4.5 / (1/100_000_000) / 100_000</gadget>
<output>4_500</output>

<result>4_500</result>