“The sensorial materials establish a solid basis for the language and mathematical materials to follow. Materials introducing literacy and numeracy (numerical understanding) to the children do not represent subject matter for the children to “learn” in the usual sense. When feasible the sensorial materials are composed of sets ten objects, giving the children an indirect exposure to the basis of the decimal system. They also represent basic measurement designations and geometrical shapes. Ten rods represent variations in length, ranging from decimeter to a meter. A hexagonal box shows that a hexagon can be made of equilateral triangles, trapezoids and rhombi.” 2
Understanding how to conduct a three period lesson is fundamental to Montessori teaching. Teachers begin using the Three Period lesson when introducing sensorial material. It is initially used to teach properties such as size but is also effective in using geometric names for shapes or so. It is a simple tool for the teacher to use and an effective learning procedure for the child. Allow the child to use the material for several times before introducing the vocabulary.
“Dr. Maria Montessori emphasizes that there is a period which comes before the three periods of Seguin. This is the period when the child works alone with the sensorial apparatus, and experiences the differential sensory stimuli without verbal interruption. This period of acquisition of sensory impression should precede the three period of Seguin.” 3
“Teachers do of course evaluate the children in Montessori; it is simply not obvious to the children that they are being evaluated. One way in which Montessori teachers evaluate children is by the manner in which they give lessons. Following Seguin, Dr. Montessori advised that lessons involving nomenclature be given in three stages, or periods. The three periods might be thought of as association, recognition, and recall. These nomenclature lessons figure prominently in Primary, because Dr. Montessori believed children should have precise terminology for describing the world. She believed that the first five years are a sensitive period for acquiring vocabulary(Montessori, 1967). Children in Montessori learn sophisticated terminology that many a educated adult does not know, but that children appear to learn easily.
The format of three period lesson is as follows. The teacher first shows the child the materials to be named- for example the rough and smooth boards, wooden tablets covered with different grades of rough and smooth sandpapers. As she or he runs fingers over each, the teacher gives the child the referring vocabulary, “rough” and “smooth”. For the second period the teacher tests the recognition:”Give me the rough one,” “Give me the smooth one.”If the child is unable to pick the right one at this second stage, the teacher does not correct the child but assumes that the child did not get the concept to begin with. The teacher would then repeat the presentation another day. If the child did correctly choose the rough one, the teacher would go on to the third period, holding up one of the sandpaper tablets and asking the child,”What is this?”A great deal of vocabulary is taught in the primary classrooms through such lessons, and they give the teacher the...