The agricultural machinery factory needs to process 2480 parts. Originally, 100 pieces were processed per day, but after 20 days of work, it was changed to 120 pieces per day. In this way, how many more days of processing can the task be completed?
农机厂要加工2480个零件．原来每天加工100个，工作20天后，改为每天加工120个．这样再加工几天就可以完成任务？
<gadget id="calculator">100 * 20</gadget>
<output>2_000</output>

<gadget id="calculator">2_480 - 2_000</gadget>
<output>480</output>

<gadget id="calculator">480 / 120</gadget>
<output>4</output>

<result>4</result>