<p>You should get together with other students and meet with someone else at the school that has authority and will look into and DO something about the unfair/inconsistent/error-ridden grading system. Talk to the counselor. Perhaps your grades could be replaced with your AP scores (5=A, etc.) If the teacher has already been “fired” for incompetence, (or is not having contract renewed), someone should be sympathetic to your and your classmates’ plight. If what you say is true, it does not sound fair to me. (And unfortunately this is a common problem/complaint in math education–teachers with poor English/poor teaching skills.) Don’t give up, but you have to be polite and calmly present all of your evidence to the right person with authority to make changes.</p>