The child
must be able to construct the binomial cube easily
before being
introduced to the trinomial cube.
MATERIAL:
Cube 1:
A cube composed
of twenty-seven wooden blocks which fit together to
form the
cube of (a + b + c). Each face that is "a2" is red, "b2"
is
blue, and
"c2" is yellow and all other faces are black.
a = hundreds
b = tens
c = units
Cube 2:
Exactly like
the first, but in plain wood. There are no painted
surfaces.
PURPOSE:
The child,
at the period of the absorbent mind, develops a
predisposition
to understand math.
CONTROL OF
ERROR:
He matches
the pieces by color. The result is a cube.
AGE:
4 to 6 years
EXERCISE:
Cube 1: Colored Trinomial
The binomial
and trinomial cubes come in both hinged and non-hinged boxes. If the box
is not hinged, use the following proceedure:
The teacher
sits next to the child at a table. Holding the lid on the box, she turns
it upside down on the table. She lifts the box off the cube carefully, and
looks at the different sides of the cube and with the child. The teacher
removes one layer of the cube at a time and places it on the table.
At this point,
the teacher may simply begin removing pieces from the hinged box, or proceed
with the layers on the table:
Starting
with the tallest layer and the red cube (a3), the teacher removes pieces
in order and lays out according to the formula. She does the same with the
second layer (selecting the piece with a red face "a2b" first),
continuing in the sequence of the formula. She is careful
to lay pieces
of the same size in front of each other. Finally, she
selects the
piece with the red face, "a2c", from the third layer
and continues
until the whole cube shows the formula in the
arrangement
of pieces on the table.
The child
and teacher spend a little time looking at the lay-out.
Then the
teacher reconstructs the cube, layer by layer, beginning
with "a3",
matching faces of the same color. The
teacher,
by the way she handles the pieces, helps the child to
understand
that she is matching faces by color. He will realize in
time that
the pieces are also matched by size. The teacher gives
help until
the child is able to work alone. Most children will
need more
demonstrations on subsequent days.
Cube 2:
Unpainted Trinomial
When the
child has had sufficient experience in working with Cube
1, he can
use Cube 2. In most cases, the teacher will need to sit
by the child
and arrange the pieces of the cube according to the
formula in
an orderly way (as with the Cube 1), and reconstruct
the cube
as the child watches. Here, the faces must be matched by
size alone.
There is no color to guide the choice. The child,
therefore,
is able to get a clearer conception of the mathematics