This frame is used for the preparation of the first presentation to the child of the plane geometrical forms.
The teacher may select according to her own judgment certain forms from among the whole series at her disposal.
At first it is advisable to show the child only a few figures which differ very widely from one another in form. The next step is to present a larger number of figures, and after this to present consecutively figures more and more similar in form.
The first figures to be arranged in the frame will be, for example, the circle and the equilateral triangle, or the circle, the triangle and the square. The spaces which are left should be covered with the tablets of plain wood. Gradually the frame is completely filled with figures; first, with very dissimilar figures, as, for example, a square, a very narrow rectangle, a triangle, a circle, an 48 ellipse and a hexagon, or with other figures in combination.
Afterwards the teacher’s object will be to arrange figures similar to one another in the frame, as, for example, the set of six rectangles, six triangles, six circles, varying in size, etc.
This exercise resembles that of the cylinders. The insets are held by the buttons and taken from their places. They are then mixed on the table and the child is invited to put them back in their places. Here also the control of the error is in the material, for the figure cannot be inserted perfectly except when it is put in its own place. Hence a series of “experiments,” of “attempts” which end in victory. The child is led to compare the various forms; to realize in a concrete way the differences between them when an inset wrongly placed will not go into the aperture. In this way he educates his eye to the recognition of forms.
Fig. 24.––Child Touching the Insets. (Montessori School, Runton.)
The new movement of the hand which the child must coordinate is of particular importance. He is taught to touch the outline of the geometrical figures with the soft tips of the index and middle finger of the right hand, or of the left as well, if 49 one believes in ambidexterity. (Fig. 24.) The child is made to touch the outline, not only of the inset, but also of the corresponding aperture, and, only after having touched them, is he to put back the inset into its place.