Participate more. Sometimes students do good but their grades are still low, which is probably the cause of low participation. During lectures, engage more, raise your hands, and try.
Learn and review your mistakes after some type of quiz.
Ask questions. If you cant handle that, use the internet. This may be my secret but I always got a headstart on whats gonna be in the math lessons cause MANY teachers copy lesson plans from such online websites.
If you are really focused on getting ur grade up, meetup with teachers after classes so they can help you.
Goodluck kid, this is just 4th grade and u need to up your game as u get in higher grade levels.