These lessons are typically given near the beginning of the school term and provide the basis for learning throughout the year.
Elementary school classrooms usually serve mixed-age 6- to 9-year-old and 9- to 12-year-old groupings; 6- to 12-year-old groups are also used. Lessons are typically presented to small groups of children, who are then free to follow up with independent work of their own as interest and personal responsibility dictate. Montessori educators give interdisciplinary lessons examining subjects ranging from biology and history to theology, which they refer to as "great lessons". These lessons are typically given near the beginning of the school term and provide the basis for learning throughout the year. The lessons also offer inspiration and open doors to new areas of investigation.[23]