On a map with a scale of 1:2000000, the distance between Beijing and Tianjin B is measured to be 2.5 cm. What is the actual distance in kilometers between the two places?
在比例尺为1：2000000的地图上，量得北京到天津乙的距离是2.5厘米，两地的实际距离是多少千米．
<gadget id="calculator">1 / 2_000_000</gadget>
<output>1/2_000_000 = around 0</output>

<gadget id="calculator">2.5 / (1/2_000_000) / 100_000</gadget>
<output>50</output>

<result>50</result>