I have several kids at home, all at different elementary grade levels and it’s not at all easy to keep them on track, motivated, and actually learning something

I have several kids at home, all at different elementary grade levels and it’s not at all easy to keep them on track, motivated, and actually learning something while trying to get work done myself. The kids have been cooped up and its hard to keep the kids from bickering. Schools are not helping. They are giving assignments but telling kids things won’t be graded or are optional, etc... so kids don’t want to do some things. We have to undo that and push them to do it. Given how competitive our society has become I am terrified that we will get behind.