A steel pipe is 4.9 meters long. Uncle Wang wants to saw it into small sections with a length of 0.7 meters each. It takes 3.5 minutes to saw each section. How many minutes does it take to finish sawing this steel pipe?
一根钢管长4.9米，王叔叔想把它锯成每段长为0.7米的小段，每锯一段耗时3.5分，锯完这根钢管共耗时多少分？
<gadget id="calculator">4.9 / 0.7</gadget>
<output>7</output>

<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<gadget id="calculator">6 * 3.5</gadget>
<output>21</output>

<result>21</result>