The actual distance is 2000 meters, the scale is 1:50000, find the distance on the map.
实际距离2000米，比例尺1：50000，求图上距离．
<gadget id="calculator">1 / 50_000</gadget>
<output>1/50_000 = around 0.00002</output>

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

<result>4</result>