When students get to middle school, they realize that they are going to have to work harder than they had to in elementary school to get good grades. They need to know how to juggle and keep up with 8 classes, how to get and stay organized, and add extracurricular activities into the mix.
In 6th grade the students take a study skills class which helps, but sometimes they need a little bit more assistance. Remind them to attend tutorials on a weekly basis and/or contact your child's counselor for further advice.