The diameter of the front wheel of the road roller is 12dm, and it rolls forward on the ground for 5 rounds, how many m does it move forward?
压路机前轮直径12dm，在地上向前滚动了5周，前进了多少m．
<gadget id="calculator">5 / 10</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">3.14 * 12 * (1/2)</gadget>
<output>18.84</output>

<result>18.84</result>