Ocr maths gcse exams grades boundries?

im a little confused of the the ocr exam points system that i need 720 to get an A*. from module 7 to 10 exams i did, the total points i got is 594 (m7=100-grade D, m8=150-grade B, m9=163-grade A m10=181-grade A*)and in my terminal exam i only need 126 to get an A*. but 126 points is an E and this is really confusing. all im asking is someone who knows the points system works and what i need to get an A*