A piece of wood is 12 meters long. To saw it into 4 sections on average, it takes 3 minutes to saw each section. How many minutes will it take to finish sawing this piece of wood?
一根木头长12米，要把它平均锯成4段，每锯一段需要3分钟，锯完这根木头一共要用多少分钟？
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

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

<result>9</result>