A piece of wood is 10 meters long, and it should be divided into 5 equal parts. It takes 7 minutes to saw the next section, how many minutes will it take to saw the wood.
一根木头长10米，要把它平均分成5段．每锯下一段需要7分钟，锯完这根木头要花多少分钟．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">4 * 7</gadget>
<output>28</output>

<result>28</result>