Every mother will send her kid to school tomorrow expecting you to reach hers.
Every kid has the potential to do and to be something positive.
It might not include straight A's in Algebra. Middle schoolers are starting to realize that just because adults say something is important doesn't mean that it is going to be important to them. Do that which is hard, get to know who these people are as individuals. Your job is not to prepare them for state assessments. Your mission, if you should decide to accept it, is to give them courage and hope for the future.