The outer diameter of a car tire is 72 cm. If it rotates 300 times per minute on average, how many minutes will it take to pass a road with a length of 8100 meters (the approximate value of π is 3).
一辆汽车轮胎的外直径是72厘米．如果平均每分钟转300周，通过一条长8100米的公路，大约需要多少分钟(π取近似值3)．
<gadget id="calculator">300 / 100</gadget>
<output>3</output>

<gadget id="calculator">216 * 3</gadget>
<output>648</output>

<gadget id="calculator">8_100 / 648</gadget>
<output>25/2 = around 12.5</output>

<result>25/2 = around 12.5</result>