Master Li processed a batch of parts, and processed 270 parts in the first 4 days to complete 20% of the production task. According to this calculation, how many days will it take to complete the remaining? (Solve with ratio)
李师傅加工一批零件，前4天加工270个零件完成了生产任务的20%，照这样计算，剩下的还要多少天才能完成？(用比例解)
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) * 4</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">4 - (4/5)</gadget>
<output>16/5 = around 3.2</output>

<gadget id="calculator">(16/5) / (1/5)</gadget>
<output>16</output>

<result>16</result>