We also have ADHD kids who struggle in school. It’s hard for kids to be motivated when they’re overwhelmed. I recommend checking his med level. He may need a bump up if he’s had a recent growth spurt. What also helps is positive reinforcement. My son earns his media time (max 1/2 hour on school days). He gets checks worth 5 minutes for following instructions (putting away lunch bag, doing chores, homework, etc) you could do something similar for school. Kids with ADHD seem to need more of the ‘external’ motivation. Also, you might check with an occupational therapist to see if your child has any sensory processing problems. Be sure to find someone who specializes in that area. Untreated sensory problems will contribute to ODD and ADD symptoms. Hang in there. It gets better!! God bless.