To repair a section of the wall, the original plan was to repair 20.5 meters per day, and the task was completed in 12 days. The actual repair was 24.6 meters per day. How many days in advance did the task be completed?
要修一段墙，原计划每天修20.5米，12天完成任务，实际每天修24.6米，提前几天完成任务？
<gadget id="calculator">12 / 24.6</gadget>
<output>0.487805</output>

<gadget id="calculator">20.5 * 0.487805</gadget>
<output>10.000002</output>

<gadget id="calculator">12 - 10.000002</gadget>
<output>1.999998</output>

<result>1.999998</result>