Uncle Ye travels by car at a speed of 50 kilometers per hour, and takes 2 hours to get from A to B. On a map with a scale of 1:4,000,000, what is the length of this route in centimeters?
叶叔叔乘车以每小时50千米的速度，经过2小时从甲地到达乙地，比例尺是1：4000000的地图上，这条路线的长是多少厘米．
<gadget id="calculator">1 / 4_000_000</gadget>
<output>1/4_000_000 = around 0</output>

<gadget id="calculator">50 * 2 * 100_000 * (1/4_000_000)</gadget>
<output>5/2 = around 2.5</output>

<result>5/2 = around 2.5</result>