**6.2 Addition and Subtraction of Integers**

**Addition of integers can be done on a**

6.2.1 Addition of Integers

1.

6.2.1 Addition of Integers

1.

**number line**.

**(a)**

**To add a positive integer**:

Move to the

**right (positive direction)**on the number line.

(b)

(b)

**To add a negative integer**:

Move to the

**left (negative direction)**on the number line.

**with the**

2. Integers

2. Integers

**same signs**are called integers with

**like signs**.

*Example:*

2 and 7, –25 and –5.

**3. Integers**with the

**different signs**are called integers with

**unlike signs**.

*Example:*

+2 and –7, –25 and 5.

**Solve the following.**

Example 1:

Example 1:

(a) 3 + (+4)

(b) 2 + (–5)

*Solution:*

(a)Therefore,

3 + (+4) = 3 + 4

= 7

**(b)**

Therefore,

2 + (–5)

= –3

**6.2.3 Multiplication and Division of Integers**

**1.**Multiplication and division of

**like signs**gives (

**+**)

$\overline{)\begin{array}{l}\text{}(+)\times (+)=+\text{}(+)\xf7(+)=+\text{}\\ \text{}(-)\times (-)=+\text{}(-)\xf7(-)=+\end{array}}$

**Multiplication and division of**

2.

2.

**unlike signs**gives (

**–**)

$\overline{)\begin{array}{l}\text{}(+)\times (-)=-\text{}(+)\xf7(-)=-\text{}\\ \text{}(-)\times (+)=-\text{}(-)\xf7(+)=-\end{array}}$

*Example:* (a) –25 ÷ 5 = –5

(b) 8 × (–5) = –40