The clock strikes 4 times at 4 o'clock, and it takes 6 seconds to finish, then it knocks 8 times at 8 o'clock, how many seconds to finish it.
时钟4点钟敲4下，6秒敲完，那么8点钟敲8下，多少秒敲完．
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

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

<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">2 * 7</gadget>
<output>14</output>

<result>14</result>