Not pregnancy, but parenting related

So my son (10 yrs old) seems to think money grows on trees. This is the 3rd time this month he's messed up (first time he "forgot" his lunch money home, he thought he had lost it, but he didn't forget his tablet!!, second time I gave him $20 for the book fair and told him to bring me back $4 as a test, obviously a Pokemon book was more important than my order, and yesterday he LOST $20 that he was supposed to give the cafeteria lady for their lunches). Sooo, now he's gonna have to pay back. Currently due to health reasons I'm not working and people don't just give me money. So, since I'm supposed to limit my activity to a minimum, I need help around here and he's got a debt, I think I can use this to our advantage as well as to teach him a lesson in hard work. Here's a list of chores I think he should be able to do, there's no time limit, so he's not gonna be enslaved but I will add them up until the $20 are repaid, and then he can have his electronics back. Think of anything else I should add?