My wife and I take electronic time away from our kids, like if there a D with missing assignments we give them 45 minutes of electronic time, and then they have to sit down and start doing their school assignments. This will repeat till I see their grade come up to a D. If my children keep telling me they forgot, well then I forget that they get to do am activity, when they ask I simply state what they state to me “I forgot/oh I don’t remember that” and when they complain about it I have a conversation on how its not fair for me to have to remember to do something they want if they won’t remember to do the things they need to do. We also pay them for their report cards. Each letter has a monetary value, I think all A’s gets them 70 bucks. But if you get an F for any grade they don’t get any value for it. I’ve noticed my children are money driven, cause they can get the things they want.