In Montessori education, children are grouped in mixed ages and abilities in three to six year spans: 0-3, 3-6, 6-9, 9-12, 12-15, 15-18. There is constant interaction, problem solving, child to child teaching, and socialization. Children are challenged according to their ability and never bored.
At each level, Montessori programs are designed to address the developmental characteristics normal to children in that stage.
Montessori classes are organized to encompass a two- or three-year age span, which allows younger students the stimulation of older children, who in turn benefit from serving as role models. Each child learns at her own pace and will be ready for any given lesson in her own time, not on the teacher’s schedule of lessons. In a mixed-age class, children can always find peers who are working at their current level.
Children normally stay in the same class for three years. With two-thirds of the class normally returning each year, the classroom culture tends to remain quite stable.
Working in one class for two or three years allows students to develop a strong sense of community with their classmates and teachers. The age range also allows especially gifted children the stimulation of intellectual peers, without requiring that they skip a grade or feel emotionally out of place.