It takes 5 minutes to saw a water pipe into two sections, and how many minutes to saw it into 5 sections.
一根水管锯成两段要5分钟，锯成5段要多少分钟．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

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

<result>20</result>