On the 1:4000000 map, the line segment of 4.6cm represents how much is on the ground.
在1：4000000的地图上，4.6cm的线段表示地面上多少．
<gadget id="calculator">1 / 4_000_000</gadget>
<output>1/4_000_000 = around 0</output>

<gadget id="calculator">4.6 / (1/4_000_000) / 100_000</gadget>
<output>184</output>

<result>184</result>