The scale of a map is 1:1,000,000. The distance between A and B on this map is 4.5 cm. What is the actual distance in kilometers?
一幅地图的比例尺是1：1000000，甲、乙两地在这幅地图上的距离是4.5厘米，实际距离是多少千米．
<gadget id="calculator">4.5 / 100_000</gadget>
<output>0.000045</output>

<gadget id="calculator">1_000_000 * 0.000045</gadget>
<output>45</output>

<result>45</result>