The radius of the wheel of a bicycle is 40 cm. When the bicycle passes through a street, the wheels make 500 revolutions. How many meters is this street?
一辆自行车的车轮半径是40厘米．这辆自行车通过一条街道时，车轮转了500圈．这条街道长多少米？
<gadget id="calculator">500 / 100</gadget>
<output>5</output>

<gadget id="calculator">3.14 * 2 * 40 * 5</gadget>
<output>1_256</output>

<result>1_256</result>