There is a flower bed with a diameter of 20m in Sun Wen Park. Xiaojun rides a bicycle with a wheel diameter of 50cm around the flower bed. How many times does the wheel turn?
孙文公园里有-个直径是20m的花坛，小军骑一辆车轮直径是50cm的自行车绕花坛一周，车轮大约转动多少圈？
<gadget id="calculator">3.14 * 20</gadget>
<output>62.8</output>

<gadget id="calculator">3.14 * 0.5</gadget>
<output>1.57</output>

<gadget id="calculator">62.8 / 1.57</gadget>
<output>40</output>

<result>40</result>