You can also get some math curricula like singapore math (with the intensive practice book and process skills word problems book) or beast academy online. I'm not sure how much they cost in your location.

Math Mammoth also sells downloadable workbooks by specfic topic so he can learn addition with carrying without having to go through a whole year's worth of busywork. He might like addition and subtraction 2b (introduces carrying) and the factoring worktexts.