- Ten solid wooden cubes varying in size from 1 cubic centimeter to 1
- cubic decimeter. These are pale pink or plain wood. A strong pink must
- not be used. If it is used, children are more aware of color than of
- size. If in plain, lightly varnished wood, a very good hard wood must
- be used.

- 1) Visual and muscular perception of dimension leading to an abstract
- understanding of size
- 2) Awareness of dimension leading to intelligent observation of size in
- the environment
- 3) Coordination of movement
- 4) Perfection of hand movements
- 5) Preparation for mathematics

- a) There are 10 cubes because 10 is the basis of our number system
- b) The largest cube would hold 1 liter, the smallest 1 cubic centimeter
- c) Preparation for cube root

- Eight of the smallest make the second cube (2
^{3}). - Twenty-seven of the smallest make the third cube (3
^{3}). - Sixty-four of the smallest cube make the fourth cube (4
^{3}),etc. - One thousand of the smallest cube make the tenth cube (10
^{3}).

- 2
^{1/2}to 5 years.

- The teacher asks the child to spread a dark green mat on the floor on
- which to work. She shows the child how to carry the cubes (two or three
- at a time) and place them at random on the mat. The teacher sits beside
- the child and builds a tower in order of size starting with the largest
- cube. Each cube is placed concentrically on the one before in one
- movement. She pauses and looks at the cubes. The child sees that a
- deliberate choice is being made. The teacher must not, however, re-
- adjust a cube after it has been placed in position as a child may think
- this is part of the lesson and copy her movements. Therefore, the
- teacher must have worked the tower until she can build it perfectly
- before giving the lesson.
- The cubes are grasped from above with fingers and thumb on four sides.
- In this way, it is possible to judge size by touch as well as by sight.
- The child may need to use two hands to put the largest one in position,
- but the teacher can grasp them all correctly and the child can grasp
- all those he or she can in the same way.

**Note: **

- With developmentally delayed children, every other
- cube may be given at first. It does not matter which five the child
- works with. The difference between any two cubes in succession will be
- twice as great as when using all ten, and the child will have more chance of
- succeeding. When the child can manage 5 well, he or she can have the ten cubes.
- The child with serious difficulty in motor control, can grade the
- pieces in a row rather than building them into a tower until his
or her

- movements are more controlled.

**EXERCISE 1**

- The child builds the tower as shown. He or she will make mistakes at first, but
- will gradually perfect the ability to judge size with practice. The
- teacher must not interfere. If the child obviously has not understood the
- lesson, then the teacher will give him or her a new lesson another day before
- he or she starts using the material. New lessons can also be given to help the
- child improve in handling the material.
- The tower must not be knocked down as the edges and corners are soon
- spoiled when this is done. The child should take it down block by
- block.

**EXERCISE 2**

- When the child does Exercise 1 easily and well, he can be shown how to build the tower with one corner of each cube exactly above the other all the way up, with the corner and two faces of the cube exactly flush. There will be two ledges, 1 cm. wide, on the other two sides of the tower. The smallest cube will fit on these ledges. The child is shown to run the cube along each ledge in turn. This exercise demonstrates the relationship in size between the cubes.

**Visual:**- a) The child can usually see his or her errors when looking at the
- completed tower.
- b) If the tower is very badly built it will fall over.

Once the child has worked with the
material for a while, and is discriminating the differences in
dimension, the "Three
Period Lesson" can be used to introduce the terminology as
appropriate.

- cube
- large, small
- large, larger, largest
- small, smaller, smallest