Geometric Cabinet (Plane Geometric Insets)

Direct aim. To see and feel differences of shape, and later to learn the names of plane figures.

Indirect aims, the ones you will not see at once

A wooden cabinet of six drawers. Each drawer holds six square frames, and almost every frame has a blue shape with a small knob. Montessori Outlet's cabinet has 35 pieces: six circles, six rectangles, seven triangles, six polygons, four curved figures, six quadrilaterals and one blank frame.

A demonstration tray that holds six frames, for the first lessons. Montessori's 1912 tray measured 30 by 20 cm and was painted dark blue, with plain wooden squares to fill the spaces not in use.

Montessori's own drawers held a square with five rectangles of the same length and shrinking width, six circles, six triangles, polygons from the pentagon to the decagon, and curved figures. The modern cabinet keeps those groups.

Three series of white cards printed with the same shapes at the same size: filled in blue, then a thick blue outline, then a thin black line. They come after the frames.

A table, with room below the tray to lay the shapes out.

1. 1Set up the tray with a circle, a square and a triangle. Fill the other spaces with plain squares and carry it to the table.Say "I'm going to show you some shapes." Then nothing more.
2. 2Lift the circle out by its knob with the thumb and two fingers, and lay it below the tray.Silent Thumb and two fingers on the knob, a slow lift.
3. 3Trace the edge of the circle slowly with the index and middle fingers, all the way round.Silent Two fingertips, slow enough that the child can follow every bit of the edge.
4. 4Trace the inside edge of the empty frame the same way. Then drop the circle back in.Silent The frame's edge is the clearer guide; let the fingers run along it.
5. 5Do the same with the square, stopping at each corner and running along each side.Silent Pause at every corner. The corners are where shapes differ.
6. 6Do the same with the triangle.Silent Three sides, three corners, at the same pace.
7. 7Take all three out, lay them on the table out of order, and invite the child to trace and replace them.Say "Would you like to try?" Then sit back.
8. 8Over later lessons, add more contrasting shapes, then fill the tray from one drawer of similar shapes: six circles, or the square and five rectangles.Silent Change one shape at a time, from contrast toward similarity.

A rectangle that won't go in sideways, beside a square that goes in any way you turn it.

The circle, which fits however it's turned.

The oval, which fits only one way round, big curve to big curve.

Two fingertips running into a corner and changing direction.

The frame. Each shape enters only its own opening, so a wrong choice simply won't drop in, and the child sees why. Montessori called the control absolute here. On the cards it moves to the eye: the wooden shape has to cover the printed one exactly.

Montessori’s name for this check is the control of error.

• Matching the wooden shapes to the three series of cards: filled, thick outline, thin line
• Laying out the cards from all three series and placing each wooden shape on its three matches as fast as possible
• Tracing and replacing with the eyes closed, a game Montessori's children invented themselves
• Finding the shapes in the house: a rectangular table, a round plate, a triangle of toast
• Tracing a frame's outline with a pencil on paper, which leads to the metal insets

Variations

This work needs only the material, so it has no printable of its own. The shelf plan below places it among the other works for the same age.

Free to print for your family, no email needed. Print at 100%, not “fit to page”, so the drawings keep their scale. Every printable on the site is listed on the printables page.

Ready for the first presentation

Ready for the next lesson

The smallest circles and the knobs are choking-size for a child under 3. Count the pieces back into the tray.

Carry the drawers flat. A tipped drawer drops six pieces at once.

We have not bought the paid homeschool curricula, so they are not listed here.

1. Maria Montessori, The Montessori Method (1912)

   Chapter XIII, Education of the Sense of Vision

   A rectangular tray 30 by 20 centimetres, painted dark blue, holds six square frames with their insets, and blank wooden squares let as few as two or three forms be presented at a time.

   A case of six drawers holds six small frames each: plain squares with a rhomboid and a trapezoid, a square with five rectangles of the same length but varying width, six circles, six triangles, five polygons from pentagon to decagon, and six curved figures.

   At first children place the insets only after many attempts, putting a rectangle with its long side across the short side of the opening, but after three or four lessons they place them with ease.

   The child touches the contour of the piece with the index finger and then the contour of the frame, and children confused about where a figure goes place it perfectly once they have touched both contours.

   In the exercise with the insets the control is absolute, since the figure can only enter the corresponding frame, so the child can work by himself.

   Chapter XV, Intellectual Education

   Lessons in nomenclature begin with two strongly contrasted forms, the square and the circle, and the square enters its frame however it is turned while a rectangle placed across the opening will not.

   Chapter XX, Sequence of Exercises

   The child passes to the plane geometric insets in metal, follows the contours with a pencil and fills in the figures.

2. Maria Montessori, Dr. Montessori's Own Handbook (1914)

   Sensory Education

   The first figures in the frame are very different, such as the circle and the equilateral triangle, with plain tablets in the other spaces, and later figures similar to one another are arranged together.

   The child touches the outline of the inset and of the corresponding aperture with the soft tips of the index and middle fingers before putting the inset back.

   Children wanted to learn all the names of the forms, even the most difficult such as trapezium and decagon, rather than only square, rectangle and circle.

   The children themselves invented the exercise of blindfolding their eyes to recognize the forms by touch, taking out and putting back the insets without seeing them.

   Sensory Education, Fig. 25

   Three series of white cards repeat the forms at the same size: filled in with blue paper, outlined with a strip of blue paper, and outlined only in black ink.

Lesson text and the scope and sequence are CC BY 4.0: reuse them with credit to Owen Wren, Homeschool Montessori, and a link. Photos and illustrations are all rights reserved. The plates from Montessori's 1912 and 1914 books are public domain and not ours. Terms.