On the 1:40000 project schematic diagram, the length of Nanjing Metro Line 1 (the section from the Olympic Sports Center to Maigao Bridge), which will be officially opened to traffic on September 1, 2005, is about 54.3cm. What is its actual length? rice.
在1：40000的工程示意图上，将于2005年9月1日正式通车的南京地铁一号线(奥体中心至迈皋桥段)的长度约为54.3cm，它的实际长度约为多少千米．
<gadget id="calculator">1 / 40_000</gadget>
<output>1/40_000 = around 0.000025</output>

<gadget id="calculator">54.3 / (1/40_000) / 100_000</gadget>
<output>21.72</output>

<result>21.72</result>