There is a group of three students that make other students feel like they can't speak up or they will be made fun of, and other students do not speak up because those three are a constant distraction in class. How can a teacher change that environment so that these three students do not intimidate the rest of the class anymore?
I feel that having a conference with each student individually is a good idea. This allows you to talk to them one-on-one and express your seriousness. If the problem persists getting the administration involved is, in my opinion, a good solution.
Talking with the students is the best option.
I agree, I would encourage others to play and break up the threesome. Allowing more kids to engage in other activities together and to build more friendships.
I think that splitting them up would make class easier, but I don't think it would solve the problem. I feel these girls would still be together in out of the classroom situations like lunch or recess, and they would still feel inclined to behave in the same manner. I think more of a head-on approach should be taken.