To enter a Montessori classroom is to enter a world specially prepared for the comfort and stimulation of the child. It's a carefully designed environment where children of mixed ages work together or independently with multi-sensory materials that invite them to touch, to think, to experience. Children move freely about, choose an activity, and work on it until a sense of accomplishment is achieved. Before the child chooses another activity, materials are put back in place. With the freedom to choose, children develop self-confidence, self-discipline, and self-mastery. Within this prepared environment, great care is taken to lead the child through successive levels of educational activities without unnecessary help from the adult. Although the children talk and move around the room at will, their absorption in their activities and their respect for each other contribute to the calm atmosphere. Children work with a concentration seldom seen at this age.