A piece of wood is sawed into 6 sections on average, and each section takes 4 minutes to saw. How many minutes will it take to complete the sawing?
一根木头平均锯成6段，每锯下一段要4分钟，锯完一共要花多少分钟．
<gadget id="calculator">6 - 1</gadget>
<output>5</output>

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

<result>20</result>