Some teachers have trouble editing their assignment percentages for the term. Each term is usually broken into the semester, the marking periods, and a final:

To get the percentages to match the weight, you need to make sure the Final Exam is set to the Semester Grading Period (Spring/Fall). To do this, find the Final Exam in the teacher's materials and open the settings:

Set the grading period:

Make sure the assignment is set as midterm/final:
