There is a piece of wood whose length is 12 meters long. It needs to be divided into 6 sections on average. It takes 4 minutes to saw each section. How many minutes will it take to finish sawing this piece of wood?
有一根木头，它的长度是12米长，要把它平均分成6段，每锯下一段需要4分钟的时间，锯完这根木头一共需要多少分钟分钟．
<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<gadget id="calculator">4 * 5</gadget>
<output>20</output>

<result>20</result>