If it takes 3 minutes to saw a steel bar into two pieces, how many minutes will it take to saw it into three pieces?
把一根钢筋锯成两段需3分钟，把它锯成3段需多少分钟．
<gadget id="calculator">2 - 1</gadget>
<output>1</output>

<gadget id="calculator">3 / 1</gadget>
<output>3</output>

<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<result>6</result>