# Colored Bead Bars: Inverse Products

From wikisori

## Contents

### Age

6-9.

### Materials

- Bbox of colored bead bars 1-10
- Chart I

### Preparation

### Presentation

- The directress asks the child to take the bar of 7, 6 times.
- The bars are lain in a column.
- Directress says: "How do we express this?"
- 7 x 6 = 42 is written down.
- Now , directress takes the bar of 6, 7 times.
- These are lain next to the others.
- When the child writes down 6 x 7 =42, he should observe that the product was the same.
- Directress says: "Are the multiplication problems the same? Notice that the two rectangles are equal, each having 42. even though the order of the factors is not the same".
- The child should observe in the written form that the factors are the same, just reversed in their positions.
- Directress gives several examples of this.

### Control Of Error

### Points Of Interest

### Purpose

- To help the child on the memorization of multiplication understanding of the commutative property of multiplication.

### Variation

### Links

### Handouts/Attachments