**BASIC OPERATIONS ON DIRECTED NUMBERS**

**TOPICS**

- Addition and Subtraction of Directed Numbers (Revision)
- Multiplication and Division of Directed Numbers
- Inverse and Identity

** **

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

### Addition

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 \(3\).

You are viewing an excerpt of this lesson. Subscribing to the subject will give you access to the following:

- NEW:
**Download**the entire term's content in**MS Word**document format (1-year plan only) - The complete lesson note and evaluation questions for this topic
- The complete lessons for the subject and class (First Term, Second Term & Third Term)
- Media-rich, interactive and gamified content
- End-of-lesson objective questions with detailed explanations to force mastery of content
- Simulated termly preparatory examination questions
- Discussion boards on all lessons and subjects
- Guaranteed learning