The length of the hour hand of a wall clock is 5 cm. From 9 am to 3 pm, what is the distance traveled by the tip of the hour hand in cm?
一只挂钟的时针针长5厘米，从上午9点到下午3点，时针的尖端所走的路程是多少厘米．
<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">2 * 3.14 * (5/2)</gadget>
<output>15.7</output>

<result>15.7</result>