The height of a teaching building is 20 meters, how many centimeters should it draw on a 1:500 paper.
一幢教学楼的高是20米，把它画在1：500的纸上应画多少厘米．
<gadget id="calculator">20 * 100</gadget>
<output>2_000</output>

<gadget id="calculator">1 / 500</gadget>
<output>1/500 = around 0.002</output>

<gadget id="calculator">2_000 * (1/500)</gadget>
<output>4</output>

<result>4</result>