Room assignments for Math common final exams (Math 109C, 111, 112, 116, 120R, 122A, 122B, 125, 129, 223) can be found at http://math.arizona.edu/academics/courses/finals.
Room assignments are not posted until a week or two prior to the date of the exam.
Note that common final exam dates and times can be found by going to the Registrar's webpage at http://registrar.arizona.edu/schedules/finals.htm and selecting the appropriate semester, and clicking on Common Final Exam Schedule.
If your math class is not included in the list of classes with Common Final Exams, the university schedule of finals (linked above) for MWF or TR classes will dictate the time and date of the final. The final exam will then be given in the normal room that your class has met in all semester.