If the minute hand of a wall clock is 20 cm long, how many meters is it to rotate the tip of the minute hand 5 times?
一个挂钟，它的分针长20厘米，则这根分针的尖端转动5圈是多少米．
<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">2 * 3.14 * 20 * (1/20)</gadget>
<output>6.28</output>

<result>6.28</result>