It takes 3 minutes to saw a piece of wood of uniform thickness into 6 sections, how many minutes will it take in total?
把一根粗细均匀的木头锯成6段，每锯一次需要3分钟，一共需要多少分钟．
<gadget id="calculator">6 - 1</gadget>
<output>5</output>

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

<result>15</result>