I have experienced ADD and ADHD in my classrooms and private tutoring. When I am confronted with a student who may have ADD or ADHD, I begin to offer many of the suggestions that have been listed in other parts of this site. Key words, reformatted time and work, support, encouragement, etc. For me, I find if these problems can be improved by using these problem solving rituals than I will consider the student as having clinical problems. Students without clinical problems do not improve-often change to create disruption in other forms.
ADDers can work with their hands and listen and learn at the same time.
Physical movement makes kinesthetic brain patterns that also link to memory for recall of facts and time-space relationships at test time. Give kids the syllabus for the entire unit. Mark on it where each lesson is, so they can see where they are, where they are going. Proactive behavior management. Don't punish the child for a teacher's failure to recognize Trouble when it's about to bite.