Perhaps you need to supervise him , and make sure he has enough time in the morning to get ready for school, chioldren hate to be rushed , when he has to do homework ,you be there and make sure he does it, dont simply leave it to him, it is possible he needs more direction.He sounds like an intelligent boy perhaps there is some laziness there,could it be the way you show him something new to solve ,does he have plenty of outside activities and sports ,ball games, children respond to Physical activities, get his Dad involved in some sport.with him.