The shoe factory needs to produce 27,540 pairs of children's shoes, and plans to produce 255 pairs per day. It actually took 102 days to complete this task. How many days ahead of schedule? How many more pairs are produced per day than originally planned?
鞋厂要生产27540双儿童鞋，计划每天生产255双，实际完成这项任务用了102天．比原计划提前几天？每天比原计划多生产多少双？
<gadget id="calculator">27_540 / 102</gadget>
<output>270</output>

<gadget id="calculator">270 - 255</gadget>
<output>15</output>

<result>15</result>