As I said maybe let him go at his own pace and see what happens ,it has also been found that a multiple vitamin supplemnt can help children with concentrating difficulties, B Complex and Vitamin C and also fish oil, these may help him,Dont push him , what will happen if you simply let him find his own way.at least to start with and see if he does his work ,let him have his own control.
I do approach him very respectfully and keep my demeanor even. At this time, my wife is in Texas so he's just dealing with me, which he has no issues about, but doesn't recognize his grandparents as authority figures. The thing is that he is easily distracted. If he is put on a task, he heads out to accomplish it, but gets distracted on the way and totally forgets what he was heading to do in the first place. When asked about the original task, he gets upset and feels like he is being pushed.When asked why he didn't complete the task, he says "I Don't Know". He knows what's expected of him, he just doesn't do it.
When he comes home let him have a drink and a snack and tell him no TV no toys till homework is done, do it quietly no yelling no demanding, simply the facts, new rules, homework first then TV and Fun , be consistant and do not punish ,no approaching him aggressivly , you will only be met with kind. try focusing on his positive side and praise him when you see him doing something right.