The distance between the two places measured on a map with a scale of 1:4000000 is 6 cm. If it is drawn on a map with a scale of 1:2000000, what is the distance in centimeters between the two places on the map?
在一幅比例尺是1：4000000的地图上测得两地的距离是6cm，如果把它画在1：2000000的地图上，两地的图上距离是多少厘米．
<gadget id="calculator">1 / 4_000_000</gadget>
<output>1/4_000_000 = around 0</output>

<gadget id="calculator">6 / (1/4_000_000)</gadget>
<output>24_000_000</output>

<gadget id="calculator">1 / 2_000_000</gadget>
<output>1/2_000_000 = around 0</output>

<gadget id="calculator">24_000_000 * (1/2_000_000)</gadget>
<output>12</output>

<result>12</result>