Do colleges just see the letter grade or can they also see the percentage?

Answered

Colleges see the grades the way your school calculates them on the official transcript your HS counselor submits. The accepted answer is not correct.

So if your school uses a 4.0 scale with a corresponding school profile that explains the weighting that is what they use and what you report on the common app. If your schools uses a 7.0 or 11.0 scale, that is what they see. And in my case my school uses a numerical 100 scale, so at my school if someone has a 90.5 GPA they see a 90.5 GPA or a 93 or 95 GPA. And then the admissions officer evaluates the applicants from my school by comparing me, for example against other students who are applying to the same school. So if 25 people apply to Columbia then the AO looks at 25 GPAs between say 88 and 95 and decides which 8 to accept and knowing there is probably a 67-75% yield rate to Columbia from my HS, 5-6 will matriculate.

Someone who is not a legacy or recruited athlete like me might need a 95/100 to get in. But someone who is both a legacy and recruited athlete might only need a 88/100. Same goes with test scores. Someone like me who isn't an ALDC might need a 1550/35+ SAT/ACT but someone who is both a legacy and recruited athlete might only need s 1350/29.

I'm giving you this example so you understand that GPA/Test Scores are a malleable input for admissions officers depending on what kind of open seats they have at the college. If they need a head cheer captain, or bassoonist or a couple male ballet dancers, well they get some leniency with GPA/Test Scores/etc. But if you are just applying as a non-ALDC, non marginalized or over-represented demographic like White or East Asian, and are not poor, you better have stats in the 75%-100% percentile because your narrative is always over-subscribed from year to year. I call it the NightClub/Bouncer paradigm. If there were no bouncers, then there would be too many over-represented people in the club and VIBE would be off or meh. That's why there are bouncers and someone with a clipboard who is recruiting VIPS and letting all the interesting/fashionable/attractive people cut through the line. It's not fair, but neither is college admissions.

Hope that makes sense to you.