Is it appropriate to express concerns to a professor about a new exam format? I'm taking a math class at community college. The class has three regular exams (25% of grade) and a final (25%). Normally, the professor generously grades the fifteen-question exams with partial credit, but because of the COVID-19 crisis, we have had to move everything online.

I received excellent scores on the first two exams, but the third exam we had to take online. In the new, twenty-question format, she obviously could not offer partial credit because a computer scored it. Going into the exam, I didn't feel unprepared, but I ended up getting a terrible 62%. But then, the professor announced that the entire class had performed poorly on the exam, and she gave us another day to retake it. I had already spent an entire day studying and working on the exam, and I knew it would be dropped anyway, so I declined. I still don't think that there was much that would have changed if I took it a second time without being able to see what I got wrong. When I did get it back, I found that several of my mistakes had nothing to do with math and were a result of failing to correctly enter my results into the computer. 

I don't know how the rest of the class performed on the exam compared to me, but the professor was concerned enough to give an extra day, so I'm willing to bet it was around the same. Needless to say, I strongly suspect that our collective failure is a result of the new exam format. I think that our grades depended on the partial-credit scoring. And now, the final, worth 25% of my grade, is coming up on May 18th.

I have a 98% in the class. If I get a 60% on the final, it will completely destroy my grade. And what's most disturbing to me is that so far, there has been no correspondence on what the final will look like. In terms of format, I don't know what I'm studying for, exactly. If it is going to be similar to the third exam, then I'm very likely doomed. With my two AP exams also around the corner, in the same week, it is causing an undue amount of stress.

I really appreciate the professor, and I naturally want to remain respectful and stay on good terms with her. Is it appropriate for me to voice my concerns? What kind of language should I use, and which parts of what I have disclosed here are appropriate to include? And what reasonably should I request?
It’s totally appropriate to point out to your professor that your grade is suffering for technical reasons having to do with the online format of the exam. If your professor is reasonable she will not be in the least bit offended by this.

By the way, we are pretty much all dealing with issues of this sort nowadays. I experienced something similar just a few days ago when I gave an online quiz. One of the problems required entering the answer to a question in decimal notation, and this was automatically graded by the testing platform. The correct answer was 15/64=0.234375, but some students assumed it was okay to round off the answer and entered 0.234 or 0.23, only to have that marked off as incorrect. When they emailed me to point out the issue, I gave them the points for the question.

To summarize, let your professor know. Be polite and explain the technical issues in entering the answers that caused your answers to be marked as incorrect. If you explain it clearly and convincingly enough, not only will the professor be in a better position to design a fairer format for the final exam, she may actually give you back some of the points that were marked off in the current exam.