The length of the minute hand of a wall clock is 1 cm. What is the distance traveled by the tip of the minute hand after 30 minutes?
一只挂钟，分针长1厘米，经过30分钟后，分针的尖端所走的路程是多少厘米．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

<result>3.14</result>