As a member of the 0.01% of the population with an IQ well over 150, I can promise you, IQ scores are not predictors of good grades. I did not get good grades in many classes in high school, even though I aced every quiz and every test. And it was because mindless drone-work (sorry, “homework”) was weighted more heavily than the exams meant to test your knowledge. Which not only doesn’t make sense, but is ultimately self-defeating, as it’s entirely possible to get C’s on every exam and every quiz but still make an A in the classes. A fact I ended up proving in Algebra II to fellow classmates. I didn’t make good grades not because I didn’t understand the material, but because boring ass homework was piled on me; hours and hours of drone-work that ultimately had no impact other than to drill in what I already knew. And I wasn’t the only high IQ with this problem; most of us who attended school with me had similar issues. A few didn’t, but enough did that during my Junior year, there was what the principles called a ‘meeting of the minds’ where they were supposed to figure out why this was happening. Even after identifying the cause, nothing changed. Do you know why? Because the ‘average’ student (read: dummies) don’t learn unless it’s mindlessly drilled into them; often not even then. Se la vie.