A 1-meter-long piece of wood needs to be sawed into 20-centimeter-long pieces. If it takes 5 minutes to saw each piece, how many minutes will it take in total?
一根1米长的木料，要把它锯成每段20厘米长的木料，如果每锯下一段要用5分钟，则一共需要多少分钟？
<gadget id="calculator">100 / 20</gadget>
<output>5</output>

<gadget id="calculator">1 * 5</gadget>
<output>5</output>

<gadget id="calculator">5 - 1</gadget>
<output>4</output>

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

<result>20</result>