Master Zhang processes a batch of parts, and plans to process 120 per day, which can be completed in 30 days. Actually process 150 per day, how many days can the task be completed in advance?
张师傅加工一批零件，计划每天加工120个，30天就可以做完．实际每天加工150个，可以提前几天完成任务？
<gadget id="calculator">120 * 30</gadget>
<output>3_600</output>

<gadget id="calculator">3_600 / 150</gadget>
<output>24</output>

<gadget id="calculator">30 - 24</gadget>
<output>6</output>

<result>6</result>