Montessori is a highly hands-on approach to learning. It encourages children to develop their observation skills by doing many types of activities. These activities include use of the five senses, kinetic movement, spatial refinement, small and large motor skill coordination, and concrete knowledge that leads to later abstraction.
Montessori classrooms are child centric. Furniture is child-sized, where no teacher's desk is present. The typical classroom consists of four areas: Practical Life, Sensorial, Language, and Mathematics. Practical Life includes activities such as buttoning, sweeping, pouring, slicing, tying, etc. Sensorial includes activities to stimulate and train hearing, touch, smell, and taste.
Most Montessori classrooms try to include ways for the children to interact with the natural world, perhaps through a classroom pet (rabbits, gerbils, mice, etc.) or a small garden where the children can plant vegetables or flowers.
In schools that extend to the upper grades, each Montessori classroom still includes an approximately three-year age range. This system allows flexibility in learning pace and allowing older children to become teachers by sharing what they have learned. The intent is to establish a non-competitive atmosphere in the classroom. The belief is that class work which is different for each child results in students who are less likely to try to follow where other children are academically.
Every activity has its place in the classroom and is self-contained and self-correcting. The original didactic materials are specific in design, conforming to exact dimensions, and each activity is designed to focus on a single skill, concept, or exercise. All of the material is based on SI units of measurement (for instance, the Pink Tower is based on the 1cm cube) which allows all the materials to work together and complement each other, as well as introduce the SI units through concrete example. In addition to this, material is intended for multiple uses at the primary level. A perfect example of this is the "Knobbed Cylinder" materials. Not only do they directly offer a sensorial lesson, but indirectly the child's grip on the cylinders paves the way for holding a pencil, and the grades of cylinders allow for an introduction to mathematics.
Other materials are often constructed by the teacher: felt storyboard characters, letter boxes (small containers of objects that all start with the same letter) for the language area, science materials (e.g. dinosaurs for tracing, etc.), scent or taste activities, and so on. The practical life area materials are almost always put together by the teacher. (All activities, however, must be neat, clean, attractive and preferably made of natural materials such as glass or wood, rather than plastic. Sponges, brooms ,and dustpans are provided and any mishaps (including broken glassware) are not punished but rather treated simply as an opportunity for the children to demonstrate responsibility by cleaning up after themselves.)
At higher grade levels, the teacher becomes more involved in creating materials since not only the students' capacities but also the potential subjects widen considerably. Many of the earlier materials, moreover, can be revisited with a new explanation, emphasis, or use; for example, the cube that a five-year-old used as an exercise in color matching is revealed to the elementary level student to physically embody the mathematical relationship (a+b)3=a3 + 3a2b + 3ab2 +b3.
A child does not engage in an activity until the teacher or another student has directly demonstrated its proper use, and then the child may use it as desired (limited only by individual imagination or the material's potentially dangerous qualities). Each activity leads directly to a new level of learning or concept. When a child actively learns, that child acquires the basis for later concepts. Additionally, repetition of activities is considered an integral part of this learning process, and children are allowed to repeat activities as often as they wish. If a child expresses boredom on account of this repetition, then the child is considered to be ready for the next level of learning.
The child proceeds at his or her own pace from concrete objects and tactile experiences to abstract thinking, writing, reading, science, and mathematics. In the language area, for instance, the child begins with the sandpaper letters (26 flat wooden panels, each with a single letter of the alphabet cut from sandpaper and affixed to it). The child's first lesson is to trace the shape of the letter with their fingers while they say the phonic sound of the letter. A possible next level activity would then be the letter boxes (small containers each with a letter on the top, filled with objects that begin with that letter). After mastering these, the child may move on to the word boxes (small containers each with a short three-letter word on the top, for example, "CAT", containing a small wooden cat and the letters C, A, T). One child might move through all three levels of lessons in a few weeks while another might take several months; however, while there is a prescribed sequence of activities, there is no prescribed timetable. A Montessori teacher or instructor observes each child and provides each with their correspondingly appropriate lessons as they are deemed ready for them.