Our elementary school has about 20-22 students per class with a teacher and a teacher aide (not certified). If a certain grade has more students then they will split the students out into an additional class, so some years we may have 2 classes of 20-22 1st graders and the next year we may have 3 classes of 18-20 1st graders. The only issue this might cause is the extra teacher will move up with the students as they go to the next grades, so some students may have that same teacher several different years. This could be a good thing or it could be a bad thing depending on how each student meshes with that teacher.