Montessori's multiage classrooms typically run in three-year cycles, 0-3, 3-6, 6-9, 9-12, 12-15, and 15-18. But what about those ages...

Montessori's multiage classrooms typically run in three-year cycles, 0-3, 3-6, 6-9, 9-12, 12-15, and 15-18. But what about those ages...