It takes 4 minutes to saw a log into three pieces, and how many minutes to saw it into six pieces.
要锯一根圆木，锯成三段要用4分钟，如果要锯成六段，则要多少分钟．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

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

<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<gadget id="calculator">2 * 5</gadget>
<output>10</output>

<result>10</result>