What you’re doing isn’t working, so it’s time to try something different, and it’s time to think outside the box.
Asking, “what can we do to keep him in his seat and do work?” is trying to push a square-peg kid into a round hole. It will never work.
Instead ask, “How can we help him participate in class, learn, and show that he’s learning?” That’s the true goal, right?
Why does he need to stay in his seat? He might work better sitting on a bean bag in the corner, or sitting on the floor, or standing at his desk, or having a ball/balance chair instead of a traditional desk chair. All of these accommodations are appropriate, and all offer the movement/fidget stimulation he needs to help his brain focus. Some classroom expectations need to be challenged because they are created for neurotypical kids, and your child doesn’t/cannot function that way.
Second, be a detective and figure out why he’s not doing the work. It could be a number of things… undiagnosed learning disability, unaddressed learning disability, environment too distracting, sensory overwhelm/sensitivity, assignments are overwhelming, struggles with initiation/doesn’t know how to start, learned helplessness, anxiety, etc… All possibilities have to be considered and “investigated.” Once you determine the cause(s), then you can address it with accommodations.
ADDitude Community Moderator, Author & Trainer on Parenting ADHD, Mom to teen w/ ADHD, LDs, and autism