Marking your own homework is when you give yourself a grade for the work that you've done. It can be helpful to do this to get an idea of how well you understand the work you did. For example, if you're studying math, you can look at the questions you answered and see if you got them all correct, then you can give yourself a score to show how well you did. This can help you figure out what you need to work on so that you can do better the next time.