You mentioned missing verbal instructions at school and "selective hearing" at home. This can be a symptom of ADHD or it can be a symptom of poor auditory processing. I might look into a full audiology exam (not a hearing test at the regular pediatrician).
Are the structured settings, like the math class, also freer from background noise, and does the teacher there speak more clearly, or at a higher volume? Are there more visual cues in some classes then in others? What is the level of routine like in the different classes? How much decision making is required in each environment?(Is seating assigned? Does the work require choosing topics, or are they assigned?) How is the seating organized? Analyzing the environments and situations where he does well and comparing and contrasting them with environments where he does poorly can give you clues to what he is really having difficulty with.
In math he actually sits in the back of the room and has been in the same assigned seat since the beginning. He had hearing tests done when he was 6; all was good. In his homeroom class, he's been moved a few times.
As of now, he's near the front and by the teacher's desk and that isn't helping. His homeroom teacher allows for some talking and it makes me wonder if she lets the kids get away with quiet chatter when they are supposed to be doing focused work. Though I've witnessed him myself in computer lab; he will do anything but what he's supposed to be doing unless you give him something interesting like research on sharks (he loves sharks).
You haven't mentioned any social difficulties, but you may want to be sure that Asperger's is ruled out. The disorganization around school, the uneven performance across assignments and domains, the willingness to challenge authority, and the sensory issues are all little flags. Great motor skills makes me lean away from this, but I'd feel awful if I didn't at least mention the possibility if this is actually what is going on.
He's very social and love sports. He's excelling in karate; especially the kata.
Thanks for the excellent input and validation the likely needs to be challenged more. The problem will be around HOW to get him into a learning environment that allows that.
