It takes 8 minutes to saw a steel pipe into 5 sections. If it is to be sawed into 20 sections, how many minutes will it take?
把一根钢管锯成5段需要8分钟，假如要锯成20段，需要多少分钟．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">8 / 4</gadget>
<output>2</output>

<gadget id="calculator">20 - 1</gadget>
<output>19</output>

<gadget id="calculator">2 * 19</gadget>
<output>38</output>

<result>38</result>