The Broad Stair or Brown Stair

MATERIAL:

Ten, brown, wooden prisms all the same length but varying height and

width from 1 centimeter to 10 centimeters (or one decimeter squared).

The end faces represent the squares of the numbers one through ten.

 

PURPOSE:

This material provides for further refinement of the ability to

discriminate differences in size by providing a material which

varies in only two dimensions. This provides:

 

1) Visual and muscular perception of dimension

2) Understanding of dimensions

3) Awareness of dimension leading to observation

4) Preparation for the mathematical mind

a) Stress on 10 again

b) Demonstrates the relationship and difference between the

squares of the numbers 1 to 10:

 

Four of the first prism make the second (22).

Nine of the first prism make the third )32).

One hundred of the first prism make the tenth (102).

PRESENTATION:

The teacher asks the child to spread a dark green mat on the floor and

has him help bring 2 or 3 prisms to the mat at a time. The teacher mixes

the prisms on the mat so they are parallel to one another but not

touching. The child sits next to the teacher on the floor. Then,

beginning with the largest prism, the teacher places it towards the top

of the mat, grasping it across its thickness with one hand. This stretch

of the hand gives a muscular impression of thickness. Next, the teacher

looks around carefully choosing the next largest prism and brings it as

close as possible to the first prism. Then using both hands, one at each

end of the block, the teacher moves the second prism so the ends are

flush.

 

The teacher continues to arrange the prisms in a stair with the sequence

building towards the teacher keeping all the lengths exactly even. The

teacher pauses after placing each prism so the child may see that she is

choosing carefully. Finally, the teacher looks at the square ends of the

prisms with the child when finished. When the child understands, he may

continue. If the teacher has completed the entire stair, she would

rearrange the prisms in random order before inviting the child to do the

exercise.

EXERCISE 1:

The child does the exercise as presented. (If he cannot grasp the

largest prism, it does not matter; he can use two hands for this one. He

can grasp the others with one hand.) The child will make mistakes at

first.

EXERCISE 2:

Later, the teacher shows the child how to hold the smallest prism with

one finger at each end and place it against each "step" of the stair,

sensorially reinforcing the difference between each successive prism.

FURTHER WORK (Possible discovery of relationships)

Sometimes children see the relationship between the pink tower and the

broad stair. They can take the pink tower and broad stair and do them

together. Some children match the largest pink cube to the largest prism

of the broad stair. Other children stand the prisms on end and place the

cubes on top. If they do this by themselves, the teacher should be

interested. However, allow them to discover this. Do not demonstrate it.

CONTROL OF ERROR:

The child can usually see his mistakes, but if he does not, the teacher

should get him to feel down the stair. He can then feel any

irregularities.

VOCABULARY:

Wide - Narrow

Wide - Wider - Widest

Narrow - Narrower - Narrowest

Prism

AGE:

2 and 1/2 to 4 years

SPECIAL CIRCUMSTANCES:

For developmentally delayed children, the teacher takes every other

prism to begin with and works with five prisms presenting the lesson in

the same manner as if with the full ten prisms. The difference will then

be much greater and the child will have more chance of succeeding. The

child builds a stair. When he can work well, using every other prism, he

can be given all ten to work with.

 

 

 

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