There is a piece of wood that needs to be sawed into 4 sections, and it takes 4 minutes to saw each section. How many minutes will it take to finish all.
有一根木料，要锯成4段，每锯开一处，需要4分钟．全部锯完需要多少分钟．
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">4 * 3</gadget>
<output>12</output>

<result>12</result>