Young children are busy exploring their world. In her research, Maria Montessori observed their development and recognized that harnessing a child's natural energy made the learning process effortless. As one Montessori student put it, "It's not that we do what we like. It's that we like what we do."

Classroom materials are scaled to fit the child and designed to intrigue them. Primary program students like to explore objects by manipulating them. As they become developmentally ready, students use the materials as a springboard to abstract concepts. Working in multi-aged groups gives children a chance to observe the way older students approach the materials, sparking imitation as well as their own interpretation.

The materials encourage the development of the senses—a child’s specialty. Students continually reinvent the materials. For example, a set of rods of varying lengths may be classified, longest to shortest, during a child’s first exploration. The next time the student chooses the rods, he or she may find that laying them end-to-end on the floor creates a maze.