Montessori classrooms provide carefully prepared, orderly, pleasing environments and materials where children are free to respond to their natural tendency to work individually or in small groups. Children progress at their own pace and rhythm, according to their individual capabilities, the school community as a whole, including the parents, work together towards the development of the child.

Key Montessori ideas emerged from the observation of children in diverse cultures and in many countries:

1. That there are four key developmental planes starting from when a child is born all the way to her adulthood: 0-6 years old, 6-12 years, 12-18 years and 18-24 years. Each of these planes has its own goals:

	0-6 years - the development of the self as an individual being
	6- 12 years - the development of the social being
	12-18 years - the birth of the adult and finding one's sense of self
	18-24 years - consolidating the mature personality

The complete development of the adult human being requires that the specific needs of each of these periods be satisfied.

2. Dr. Montessori saw development as a series of periods (birth to age 6, 6-12, and 12-18 years), like repeating waves, each with its own particular strengths and sensitivities. She believed that even young children can approach big, abstract topics like the earth's geography through sensorial exploration and guided construction of knowledge.

3. That in addition to these age-specific sensitivities, human beings have a number of behavioural tendencies that give each child the ability to adapt to his or her place and time. These human traits-for example, to explore, order, manipulate, imagine, repeat, work and communicate-have been crucial to human evolution and are active within the child.

Sources:
Angeline Lillard. Montessori: The Science behind the Genius
http://montessoricentenary.org/