It takes 6 minutes to saw a piece of wood into 3 sections, how many minutes will it take to saw it into 7 sections?
一根木头，锯成3段后用6分钟，锯成7段后需用多少分钟分钟．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

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

<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<gadget id="calculator">3 * 6</gadget>
<output>18</output>

<result>18</result>