The farm tool factory produced a batch of small farm tools. It was originally planned to produce 120 pieces per day, and the task could be completed in 28 days. In fact, 20 more pieces were produced every day. How many days can the task be completed in advance?
农具厂生产一批小农具，原计划每天生产120件，28天可完成任务，实际每天多生产了20件，可以提前几天完成任务？
<gadget id="calculator">120 * 28</gadget>
<output>3_360</output>

<gadget id="calculator">120 + 20</gadget>
<output>140</output>

<gadget id="calculator">3_360 / 140</gadget>
<output>24</output>

<gadget id="calculator">28 - 24</gadget>
<output>4</output>

<result>4</result>