If it takes 9 minutes to saw a piece of wood into 4 pieces, how many minutes will it take to saw it into 6 pieces?
把一根木头锯成4段需9分钟，锯成6段需要多少分钟．
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">9 / 3</gadget>
<output>3</output>

<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<gadget id="calculator">3 * 5</gadget>
<output>15</output>

<result>15</result>