In ancient times, people used stone mills to grind noodles. If the radius of the stone mill is 1.5 meters, how many meters is it to go around the stone mill?
古代人们用石碾来磨面，石碾的半径如果是1.5米，那么绕石碾转一圈大约是多少米？
<gadget id="calculator">3.14 * 1.5 * 2</gadget>
<output>9.42</output>

<result>9.42</result>