A piece of wood is 20 meters long, and it needs to be sawed into 5 sections on average. It takes 5 minutes to saw each section, how many minutes will it take to finish sawing.
一根木头长20米，要把它平均锯成5段，每锯下一段要5分钟，锯完要多少分钟．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

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

<result>20</result>