A primary school in our city carried out the "For a Green Home" activity and continued to carry out afforestation activities this year. The original plan was to plant 500 trees a day, which took 12 days to complete. The actual planting of 250 more trees was completed a few days earlier than the original plan. Task?
我市某小学开展"为了绿色的家园"活动，今年继续开展植树造林活动，原计划每天植树500棵，需12天完成，实际每天比原计划多植树250棵，实际比原计划提前几天完成任务？
<gadget id="calculator">500 * 12</gadget>
<output>6_000</output>

<gadget id="calculator">500 + 250</gadget>
<output>750</output>

<gadget id="calculator">6_000 / 750</gadget>
<output>8</output>

<gadget id="calculator">12 - 8</gadget>
<output>4</output>

<result>4</result>