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# BASIC OPERATIONS ON DIRECTED NUMBERS

TOPICS

1. Addition and Subtraction of Directed Numbers (Revision)
2. Multiplication and Division of Directed Numbers
3. Inverse and Identity

## Addition and Subtraction of Directed Number Line (Revision)

To add using the number line, we move to the right (forward) of the number line counting each step till the addition is complete. The number at the end is the result of the addition.

### Subtraction

To subtract using the number line, we move to the left (backward) of the number line counting each step till the subtraction is complete. The number at the end is the result of the subtraction.

1. Try out the exercises on this worksheet using the first representation as an example.

2. Use the number lines to solve each problem.

## Multiplication of Directed Numbers

Multiplication is a short way of writing repeated additions. For example,

$$3 × 4 = 3$$ lots of $$4$$

$$= 4 + 4 + 4$$

$$= 12$$

With directed numbers,

$$(+4) + (+4) + (+4) = 3$$ lots of $$(+4)$$

$$= 3 × (+4)$$

The multiplier is $$3$$.

Lesson tags: JSS2 Mathematics, JSS2 Mathematics Evaluation Questions, JSS2 Mathematics Evaluation Questions First Term, JSS2 Mathematics First Term, JSS2 Mathematics Objective Questions, JSS2 Mathematics Objective Questions First Term, Mathematics Lesson Notes, Mathematics Objective Questions
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