If the wall clock strikes 3 times at 3 o'clock, it takes 6 seconds to finish, then 9 times at 9 o'clock, how many seconds to finish.
挂钟3点钟敲3下，6秒敲完，那么9点钟敲9下，多少秒敲完．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">9 - 1</gadget>
<output>8</output>

<gadget id="calculator">3 * 8</gadget>
<output>24</output>

<result>24</result>