## NUMBER Balance

#### • NUMBER

#### • algebra: equations, equivalence

The Number Balance relies on the principle of equivalence. Weights are placed on either side of the fulcrum or pivot point. If a weight is placed on the peg marked 8 on the right arm of the balance then it may be ‘balanced’ by placing a weight on 6 and another on 2 on the left arm of the balance. The equation 8 = 6 + 2 is formed. Six may be balanced with 5 and 1, and by placing two weights on 3. This basic idea may be extended into early algebra.

## Mathematical Language

Balance, equivalent, fulcrum, pivot, weighs more, weighs less, weighs the same.

## Using the NUmber balance

The Number Balance may be used to learn about addition and particularly about the commutative property of addition, that is 6 = 4 + 2 and 2 + 4 = 6. Links to equations such as 2 + 2 + 1 + 1 = 4 + 2 may be made. The ideas of greater than and less than may be explained using a number balance. subtraction, multiplication and division may all be explored using a number balance. Later early algebra concepts may be introduced.

Greater than / less than

5 > 2

Subtraction

4 + ? = 7

Addition

7 + 3 = 10

6 + 3 + 1 = 10

Multiplication

4 x 3 = 12

Division

12 ÷ 3 = 4

## Typical Classroom Requirements

A class set:

One mini balance between two children.

## Support and Complementary Materials

Algebra Tiles

(2x²-x²) + (4x- x) + (1-3)