Live classes typically run for 60 to 90 minutes one day a week. Math classes run for 45 minutes twice each week. Some classes meet for 16 sessions each semester and some for 15 (32 or 30 sessions yearly). This may vary slightly depending on the class. Please see the class description for more information. Time is available during class for discussion and questions. Students are expected to interact during class by asking questions and making comments when prompted. Weekly classes are not meant to be a substitute for homework and class preparation. If students do not ask a lot of questions, classes may be shortened. Class duration is an estimate, not a standard.