ADD or Personality Difference?

Question:

I have a 7 year old son. He is handsome, kind, and very intelligent. The problem is that he can’t sit still in class. He is often out of his seat, making noises, whistling, not paying attention, not staying on task and not completing his classroom assignments. He also is constantly talking back and arguing with the teacher. I don’t have these problems at home–maybe, because he can burn off the energy. He spends his time biking, playing with the other children and running. He is very active. I keep in close contact with the teacher. I’ve had him to see a doctor, who is sending him to see a specialist, but we (the teacher and I) need some help on disciplining him for his actions in the meantime. I love my son very much, but his behavior is hurting him. He losing self confidence and the other children are calling him bad. I hate this word. Thank you.