The scale of a picture is 1:4000000, the distance between AB and AB is 140km, how many centimeters should be drawn on this picture.
一幅图的比例尺是1：4000000，AB两地相距140km，画在这幅图上应是多少cm．
<gadget id="calculator">1 / 4_000_000</gadget>
<output>1/4_000_000 = around 0</output>

<gadget id="calculator">140 * 100_000 * (1/4_000_000)</gadget>
<output>7/2 = around 3.5</output>

<result>7/2 = around 3.5</result>