My ADHD son does better when he gets physical activity before we start. He also has a very limited attention span, but he drives me nuts because I have to drag him to the table (or couch) when it’s time to work. So, I get tired of all the contention!!! For a while, he was even running out the door when I called him to school work.
My dh saved the day. He told him that any day that he didn’t get done with school, he had to sit with dh from after dinner to bedtime and do school (whatever was easy for dh to teach). My son hated it. The next day, he would be an angel. Dh usually ends up doing this about once a week.
My son doesn’t respond to rewards except for play time on the computer. Nothing else is “worth it” to him.
I tried to do hands on stuff with him, but he really doesn’t care about that. He just wants to play. So I just try to get his lesson in as quick as I can before he can’t take it anymore. He is very smart, fortunately.
It’s not easy. I comfort myself that he would be miserable in school and I would still be doing school with him (homework). I also make a point to offer up my teaching time with him every day. And, I try to make sure that my voice stays calm and soothing.
There’s a website that talks about teaching ADHD kids, but the suggestions haven’t helped my son.

I don’t know why. I guess every kid is different.
sizzlebop.com/
Things that help him: lots of exercise, lots of friend time, me being firm and patient, dh backing me up, and little screen time (seems to acerbate bad behavior.