If it takes 9 minutes to saw a cuboid with a square base into 4 small cuboids, how many minutes will it take to saw it into 7 segments?
将一个底面为正方形的长方体若锯成4个小长方体需要9分钟，那么若锯成7段，需要多少分钟．
<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<gadget id="calculator">4 - 1</gadget>
<output>3</output>

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

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

<result>18</result>