200 cm long wooden strip needs to be sawed into 4 sections, and each sawing takes 3 minutes (sawing can not be overlapped), how many minutes will it take to finish sawing.
一根200厘米长的木条，要锯成4段，每锯一次需要3分钟(锯的时候不能重叠)，一共要用多少分钟锯完．
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<result>9</result>