A factory produces a batch of parts, and 30% of the task is produced in 6 days. According to this calculation, how many days will it take to complete this batch of parts? (use at least 4 methods)
某工厂生产一批零件，6天生产了任务的30%，照这样计算，完成这批零件还需多少天？(至少用4种方法)
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">6 / (3/10)</gadget>
<output>20</output>

<gadget id="calculator">20 - 6</gadget>
<output>14</output>

<result>14</result>