On a map with a scale of 1:4500000, the distance between Jiaxing and Shanghai is 3 cm. What is the actual distance between Jiaxing and Shanghai in kilometers?
在比例尺1：4500000的地图上，量得嘉兴和上海两地的距离为3厘米，嘉兴和上海的实际距离为多少千米．
<gadget id="calculator">1 / 4_500_000</gadget>
<output>1/4_500_000 = around 0</output>

<gadget id="calculator">3 / (1/4_500_000) / 100_000</gadget>
<output>135</output>

<result>135</result>