The diameter of the outer wheel of a bicycle is 50cm, and the length of a bridge is 314m. How many revolutions does the wheel need to rotate when the two bicycles pass the bridge?
一辆自行车的外轮直径是50cm，一座大桥长314m，这俩自行车通过这座大桥，车轮大约要转动多少圈？
<gadget id="calculator">3.14 * 0.5</gadget>
<output>1.57</output>

<gadget id="calculator">314 / 1.57</gadget>
<output>200</output>

<result>200</result>