For example, if Student get a C in AP Calculus, but gets 800 on the SAT Math 2, how much - if any at all - would this be “made up for” in the admissions process?
I would assume it would help show that the class was tougher, but I can also see that subject tests are only an hour long while a class is yearlong.
If the school truly has grade deflation, it would show on the GPA range on the school profile that the GC sends to colleges. Although I seriously doubt that grade deflation alone would explain a C. And as mentioned above, The M2 test does not cover calculus. An AO may view a 5 on the AP exam as validation of a tough grader, but even then, I have my doubts.
Subject tests wouldn’t help make up for a poor grade in a class. They could, however, re-inforce a good grade- like if you got an 800 on math II it would back up your A in math class.
Colleges are looking for strong students, not strong test takers. Intellectual curiosity, determination and dedication over a semester, which are predictors of college success, are exhibited by your grades.
That being said, a C is a single class is not going to automatically disqualify you from consideration either.