I’ve been having some trouble in Algebra 2 recently, and typically during math classes, as the teacher is explaining a concept, I think about it, and I slowly understand it, and make it make sense in my head, which has helped me immensely. However, this year, my teacher often goes extremely quickly, as she is trying to stuff as many examples in as possible in the lesson, but I get extremely confused as she goes so quickly.
She calls on me all the time, more than the typical student, in order to make sure I am understanding the material, but of the late, I’m not. She asked me to solve this problem recently, which I had NO idea how to do, and I was just embarrassed and I tried solving it. One guy even pointed out, “the test is on Friday, why don’t you understand this already?” and the entire class laughed, and whenever she calls on me, people laugh because they KNOW I’ll get it wrong. For students she likes, that she knows are getting confused in the class, when the student is unsure and starts going silent, she often gives them hints when she puts them on the spot to answer a question, but for me, she just lets me go silent and watches as the whole class berates me for being an idiot.
I don’t really know what to do to make her stop. It actually hurts a lot when everyone is snickering, waiting to remind you that you are an idiot when you don’t understand something. I’ve tried everything, from looking like I’m taking notes, to not meeting her gaze, and I never have a confused look on my face. I try to solve everything, but I’m just a bit slower than everyone else. What do I do?
She might just be continuing to call on you to see if you are understanding the material. I’d suggest going to her tutorials and hopefully her actually seeing you put in the effort will lower theses incidents, if the tutorials don’t help.
I’d suggest you talk to her.
She probably thinks that you just aren’t paying attention and she’s trying to motivate you to pay attention-- not that I necessarily agree with what she’s doing, but I suspect that’s it.
Although I would suggest you start reading ahead in your textbook and starting sooner than everyone else since you need more time, so then you can follow the material. If you can put the “slowly wrap your head around it” step before class, then you’ll prove to her that you’re putting in effort, and if she doesn’t stop then you might be less embarrassed.
Do a few practice problems ahead of time, too. Then you should have better luck understanding.
It might seem like a lot of work, but it’s actually pretty common for teachers to require that you read the chapter ahead of time.
Also, Khan Academy is good because you can pause the video.
For what it’s worth, I do disagree with the way your teacher is handling things. I don’t want you to think that I’m trying to blame you or anything.
You may have a learning disability in calculations.
Tell your teacher that you feel that you are being “bullied” when she puts you on the spot, because this set-up allows all of the students to laugh and mock you and that it is hurtful. That will shut her up quickly. If she responds defensively, go with your parents to meet with the VP.
Tell her that you will need her help in going to the vice principal to ask about being evaluated for a learning disability.
Agree with aunt bea. It sounds like there’s a possibility of dyscalculia. Take aunt bea’s advice. Good luck. 
Not everyone processes things in the same way. My husband,who is an engineer and exceptionally bright, processes verbal information rather slowly. If someone explains a new concept to him verbally and quickly, he tends to shut down (although he has learned ways to get around it). If you put the same concept in front of him in writing, he soaks it up immediately, and much more quickly than most others. You might not be a verbal learner and there is nothing wrong with that. However, it sounds like the teacher is being a bit of a bully. She may not even realize how damaging her approach is. No one should be made to feel like they are the butt of a joke, especially in a learning environment. Try to work up the courage to approach her (this is a really hard thing to do sometimes, especially for teens) outside of class and explain that you are having a hard time responding to her questions in class. Tell her that you need time to process the information and to soak it in and are becoming very uncomfortable in her class when you are put on the spot. Hopefully she will respond in a mature way. If you are having a hard time in general understanding the class material, you might do as others have suggested and try to read ahead so that the material isn’t so new when she covers it in class. Good luck!