The Montessori environment contains specially designed, manipulative "materials for development" that invite children to engage in learning activities of their own individual choice. Under the guidance of a trained teacher, children in a Montessori classroom learn by making discoveries with the materials, cultivating concentration, motivation, self-discipline, and a love of learning.
Montessori education is a flow experience; it builds on the continuing self-construction of the child—daily, weekly, yearly—for the duration of the program. Although Montessori schools are divided into multi-age classrooms—parent infant, preschool or Children's House (ages 2.5 to 6), lower and upper elementary (ages 6 to 9 and 9 to 12), and adolescent Erdkinder program (ages 12 to 15)—the prepared environments introduce an uninterrupted series of learning passages, a continuum.

The prepared environments described in this section, along with their physical dimensions, desired outcomes, and documented results, carefully reflect the natural learning characteristics of the child at each stage of development. In Maria Montessori's metaphorical language, "the successive levels of education must conform to the successive personalities of the child."

The prepared environments and the role of the teacher in the classroom distinguish Montessori from other educational approaches. For example, independent activity constitutes about 80% of the work while teacher-directed activity accounts for the remaining 20%. The reverse percentages are generally true for traditional education. The special environments enable children to perform various tasks which induce thinking about relationships. The prepared environment also offers practical occasions for introducing social relationships through free interaction. The logical, sequential nature of the environment provides orderly structures that guide discovery: Theorems are discovered, not presented; spelling rules are derived through recognition of patterns, not merely memorized. Every aspect of the curriculum involves creative invention and careful, thoughtful analysis. In viewing learning outcomes at each Montessori level, it must be emphasized that why and how students arrive at what they know is just as important as what they know.