A circular runway, with a difference of 1 meter between the inner and outer lanes, Xiao Ming runs on the inner lane, and Xiao Gang runs on the outer lane, and each runs a circle. Xiao Ming runs about how many meters shorter than Xiao Gang.
一个圆环形跑道，内外道相差1米，小明从内道，小刚从外道，各跑一圈，小明比小刚少跑约多少米．
<gadget id="calculator">2 * 3.14 * 1</gadget>
<output>6.28</output>

<result>6.28</result>