# Analysis of the Squares: Trinomial

## Contents

6-9.

### Materials

• Box of colored bead bars 1-10
• One each of the squares of 1-10
• Rubber bands

### Presentation

1. This time we'll decompose the square in a different way.
2. Count 3 along one side, and place the rubber band around the square.
3. Count 3 along the other side and put on a rubber band.
4. Now continue counting 5 more beads, and put a rubber band around.
5. Do the same on the other side.
6. Directress asks the child; "Into how many parts have we decomposed the square?".
7. Observe how each of the 9 parts is composed.
8. Notice the three squares which all lie on the diagonal, and the various rectangles formed.
9. As before, we'll construct the squares as we write it all down.

3 x 3 = 09
3 x 5 = 15
3 x 2 = 06

30

5 x 3 = 15
5 x 5 = 25
5 x 2 = 10
+50

2 x 3 = 06
2 x 5 = 10
2 x 2 = 04
+ 20
= 100

### Control Of Error

Compute the sums of the three columns and add them together. Then slide all the bead bars toward the center, and place the 100-square on top. These are the two ways to prove that this equals one hundred.