Montessori educators establish special environments to meet the needs of students in three distinct age groups: infancy to 2½ years, 2½ to 6½ years, and 6½ to 12 years. The students learn through activities that involve exploration, manipulation, order, repetition, abstraction, and communication.

Children from infancy to the age of six develop mentally through their senses. Thus, Montessori educators encourage students in the first two age groups to use their senses of touch, sight, hearing, smell, and taste to explore and manipulate materials in their immediate environment. Children from six to 12 years of age can deal with abstract concepts based on their newly developed powers of reasoning, imagination and creativity. Montessori educators assist these children by presenting special lessons and materials. After a presentation, instructors help the students explore the topic independently. In most cases, the students carry out their exploration in groups made up of classmates who are of different ages and who have chosen to work with one another. The groups then report their findings to the entire class, both orally and in writing.

The Association Montessori Internationale (AMI) sets international standards for the education of Montessori teachers and teacher trainers and for Montessori schools. The AMI headquarters are in Amsterdam in the Netherlands.