The radius of a car wheel is 0.3 meters. If the wheel rolls forward 50 times, how many meters does it travel?
汽车车轮的半径为0.3米，车轮向前滚动50圈，前进了多少米．
<gadget id="calculator">2 * 3.14 * 0.3</gadget>
<output>1.884</output>

<gadget id="calculator">1.884 * 50</gadget>
<output>94.2</output>

<result>94.2</result>