SAT Math II: 750
US History: 620 <---- i cri, didn’t really study for it
I have a 32 on ACT(35 E, 31 on rest, 10 out of 12 W), QB finalist, bunch of achievements in DECA(first in state, top 20% at international conference), leadership positions
I also have decent grades, pretty much all A’s and 1 B+ every year. Bunch of AP and honors classes
Ranked 18/481 weighted, and 3.87 cumulative GPA unweighted.
Not a lot of details, but I just really want to know if my other characteristics will offset that 620.
Your other characteristics look like most applicants’ at UPenn. If they’re looking for an excuse to reject some of the 30,000+ students who apply each year (they need to winnow this group down to 2,500 or so), that might be it, so see if you can retake that subject test in November (don’t know if the late registration deadline is past) or December.
so just retake US History or retake both tests?
Just the US History - 750 Math 2 is fine.
What’s more likely: an increase in your Math II score, or a drop of more than 20-30 points? The answer to that question should inform your choice. Your current score is around the 80th percentile, as nearly 10% of test-takers get an 800.
Definitely retake US history, but the decision on math is up to you.
Also, don’t forget that Penn wants to see all of your scores, so @NotVerySmart raises a good point about the Math.
“Just” Penn??? I think the other 3 undergraduate schools might have something to say about that. 
But to answer the question, I’d either retake USH or try another subject test.
lol I’m only in the 62 percentile for Math II. Also, my parents want me to switch to a more “useful” subject test like Biology… Do subject tests really affect what undergraduate schools will accept you, or do they value the score over the topic more?
Sorry for so many questions
Ah, my bad. The Google turned up some rather old percentiles (07-08).
I think as long as you avoid subjects like Korean/Chinese (for which a 790 would put a student in the bottom half of all test-takers), the specific test doesn’t matter all that much.
If the school does not require/recommend specific tests, you are free to choose your own, although if you are a native speaker of a foreign language, I’d avoid that test, at least for admissions purposes.