If you’ve visited a Montessori classroom, you’ve seen some of the Sensorial materials – the Pink Tower, the Brown Stair, the Red Rods. They are the ones that stand out on the shelf, and that’s no accident! Year after year, the younger children in the classroom are magnetically drawn toward these materials. The Sensorial area addresses more than sight, though. Also in the Sensorial area are works like “Smelling Jars”, “Rough and Smooth Boards”, “Baric (Weight) Tablets”, "Sound Boxes", and many more. All of the Sensorial materials introduce the concepts of gradation, relationship, and comparison. "Which one weighs more?"... "Which one is the biggest?"... "The smoothest?"... "Which jars smell the same?" The materials give the children concrete experiences that help to distinguish sensory impressions in order to define and to refine their knowledge of the the world.
Many of the materials in Sensorial are indirect preparation for math and language development. Grasping the wooden knobs of the wooden "cylinder blocks" trains the child's hand with the prehensile grip needed to write properly with a pencil. "Rough and Smooth Boards" prepare the child for tracing Sandpaper Numbers and Letters both. The Red Rods prepare the child for counting and quantity. The "Binomial Cube" and the "Trinomial Cube" are blocks with sides of red, black, yellow and blue. Chlidren follow a construction pattern on the lid to fit them into a wooden box. Elementary level Montessori students later use this same material when learning how to calculate the cubes of binomials (numbers with two digits taken to the third power) and trinomials (three digits to the third power).
Presentations in all areas follow the classic Montessori three-period lesson: 1) Introduction of concepts along with the material. For example: showing how to match pairs of color tablets, the teacher will point to them and give the concept, "This is blue...this is red...this is yellow". 2) Reinforce understanding: "Can you point to the red one?"..."Can you pick up the blue tablet?"..."Which tablet is yellow?" This is the vital part of the lesson and involves much repetition until the teacher sees the child is confident enough to move on to the third or "testing" period. 3) Pointing to a tablet she asks, "What is this?" ...Picking up a different one she asks, "Can you remember this color?"...This period also involves repetition and variation to ensure the child's solid integration of the concepts.
"And if we look at the sensorial apparatus which is able to evoke such deep concentration (remarkable in very small children between the ages of three and four), there is no doubt that this apparatus may be regarded not only as a help to exploring the environment, but also to the development of the mathematical mind."