It takes 3 minutes to saw each section of a piece of wood. How long does it take to saw this piece of wood into 6 sections?
一根木头每锯下一段要3分钟，现把这根木头锯成6段，一共需要多少分钟．
<gadget id="calculator">6 - 1</gadget>
<output>5</output>

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

<result>15</result>