It had seven illustrations of materials which a trained Montessori teacher uses to teach numeration in units, tens, hundreds, and thousands as early as preschool the Number Rods, Counter Chips and the Golden Decimal Beads. Parallel numeration of ten numbers up to 1000 use the Seguin Boards and the Chains of 100 and 1000.
This time, I will show how the abstract high school Math program made up of Algebra, Geometry and Trigonometry is given as early as grade school in an authentic Montessori school to match the strong intelligence of seven to 12 year olds.
Since computers correct errors or automatically provide answers on the screen, the childs mind which is the focus of enrichment deteriorates instead. Thus, the modern child, usually the affluent ones with home or school computer, becomes mentally lazy because he gets addicted to these cyber machines. WHAT IS WORSE IS THAT PARENTS ENCOURAGE THIS. Note that even mentally handicapped children can handle computers.
Traditionally, one is made to memorize the multiplication tables of 2 to 10 in grade school. My public school teacher in Grade 3 at San Andres Elementary School made me stay after class since I could only multiply up to Table 6. Looking back I realize that the act of memorization is similar to the force of a pressure cooker. It does not require comprehension. After a while the child forgets.
I did not realize that the other operations like addition, subtraction and division also had their own sets of tables for memorization until I did the Montessori Elementary School Teacher-Training Course in Bergamo, Italy. Montessori children from Grades I to III concentrate on these memorization tasks aided by special apparata with built in control of error. These save a young sensitive child from many heart-breaking humiliations.
Note how the bead squares along the "vertebra" column can be converted to bead cubes. As early as the second grade when the Montessori arithmetic operations focus on multiplication since first graders master addition and subtraction, what we know as the Pythagoras Multiplication Board (usually printed in the back of old school notebooks) is actually the Decanomial Multiplication Bead Board exercise (see Fig. 1).
This exercise makes use of 55 colored bead bars for each unit of 1s (red), 2s (green), 3s (pink), 4s (yellow) to 10s (gold) in a box with 10 sections. The fixed squares and fixed cubes for converting the loose bars, as I will describe later, come from the Board of Powers.
Instead of a child memorizing alone, a group of three students would lay out the multiplication tables in three ways. First, the "vertical presentation" of beads like Table 1 1x1, 1x2, 1x3, 1x4; Second, the "horizontal presentation" of beads 1x1, 2x1, 3x1, 4x1, etc. The children recite the multiplication table as they lay them out.
The third way of multiplication is the "angular presentation". Thus, the child multiplies vertically 1x1, 1x2, 1x3, and horizontally by pairs, 1x1, 2x1, 3x1, etc. As this presentation is done, the child will realize that 1x2 is just the same as 2x1 because they have the same products. This is the Commutative Property of Multiplication.
To reinforce the mastery of the multiplication products, the bead bars and the bead squares along the diagonal vertebra" are later converted into numbers to become the Numerical Decanomial Chart (Fig. 2).
Figure 2. "Numerical Decanomial" Multiplication Tables citing products in numerals, replacing the Bead Decanomial Chart
The second passage involves the "Formation of Cubes" from the squares formed in the first passage. If the squares are put together then a cube will be formed. For example, if the 2 squares of 2 are placed on top of each other then the cube of 2 or 23 is formed. The cube of 3 is done by stacking the 3 squares of 3, the cube of 4 with 4 squares of 4, etc. This passage is capped by putting the cubes on top of each other forming a tower similar to the Pink Tower used in the Montessori preschool.
Figure 3. Numerical Decanomial converted into Algebraic Decanomial
This passage starts with the substitution of numbers 1 to 10 with the first ten letters of the alphabet a, b, c, d, e, f, g, h, i, j. The perfect squares along the "vertebra" column of the Numerical Decanomial are changed first 12-a2, 22 -b2, 32 = c2, 42 = d2 until 102-j2 to form the Algebraic Decanomial. At this point, the terms monomial and binomial should have been introduced like a 2, b2, c2, and ba, ca, da, etc.
The next presentation of this passage is when the child constructs a special notebook, which is called The Algebraic Booklet made up of six pages showing the progression of algebraic lessons on simplifying polynomials. This booklet will now help the child understand the idea of like and unlike terms as well as the application of Commutative Property of Multiplication to Algebra. It also introduces the child to simple addition and grouping of terms.
Figure 6. Sensorial Proof of Euclids Theory
Above Figure 5(A) shows a small parallelogram while (B) shows a bigger parallelogram. Figure 5(C) shows a right-angled triangle with the squares built on its two short sides or the catheti and its longest side or the hypotenuse. Notice that the biggest square is divided into two rectangles by the extension of the altitude of the right-angled triangle.
With Figure 6, "Sensorial Proof of Euclids Theory," if the two rectangles of the biggest square were removed, the small parallelogram and the bigger parallelogram (from Fig. 5) can fit in the empty space, as the triangle is slid downwards to the bottom of the space left by the biggest square. Thus, by sensorial exploration, the First Passage shows that the two rectangles are equivalent to the two common parallelograms.
The Second Passage (a), shows that when the square built on the shortest leg of the triangle is removed and the triangle is slid leftwards, the small parallelogram [from Fig. 5(A)] can occupy the empty space horizontally. This shows that the square built on the short leg of the triangle is equivalent to the smaller parallelogram.
On the other hand, in Second Passage (b), if the bigger square is removed and the triangle is slid rightwards to the upper half of this vacated space, then the lower half of the bigger parallelogram can fit in the empty space plus the space vacated by the triangle. This shows that the square built on the longer leg of the triangle is equivalent to the bigger parallelogram in Figure 5 (B).
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