Analysis: According to the meaning of the question, walking 80 meters per minute is 6 minutes earlier, that is, walking 80×6=480 meters more, walking 50 meters per minute and walking 3 minutes later, that is, walking 50×3= 150 meters less, and the distance difference is 480+ 150=630 meters.

Answer: Solution: (80× 6+50× 3) ÷ (80-50) = (480+150) ÷ 30,

=630÷30,

=2 1 (minutes).

(2 1+3)×50

=24×50,

= 1200 (m).

A: So Xiaoming's home is1200m away from school.

So the answer is: 1200.

Comments: On the basis of finding the surplus and deficiency distance according to time × speed, finding the scheduled time according to the difference between (surplus and deficiency) ÷ twice allocation = the number of participants allocated is the key to complete this question.