The actual distance between A and B is 210 kilometers. On a map with a scale of 1:3000000, what is the distance in centimeters between A and B?
甲、乙两地的实际距离是210千米，在比例尺是1：3000000的地图上，甲、乙两地的距离是多少厘米．
<gadget id="calculator">1 / 3_000_000</gadget>
<output>1/3_000_000 = around 0</output>

<gadget id="calculator">210 * 100_000 * (1/3_000_000)</gadget>
<output>7</output>

<result>7</result>