Chapter 1 Integers (1.1 and 1.2)

Chapter 1:
Rational numbers



1.1 Integer

What Are Integers?

a) A positive or negative whole
numbers, including zero , is called an
integer

Activity: Recognise and then circle the integers

1.1 (a) Positive & Negative Numbers

a. Positive number – a
number greater than
zero.

0123456

b) Negative number – a
number less than zero.

-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6



Examples of (+) & (-) Numbers in real life situation
(a)Temperature

High
temperature

(positive numbers)

Low temperature

(Negative numbers)

Negative Numbers Are Used to
Measure Under Sea Level

30
20
10
0
-10
-20

-30
-40
-50



Hint

◼ If you don’t see a negative
or positive sign in front of a
number it is positive.

+9

1.1(c)Integers on a number line
Left Right

Less than 0 More than 0

0

1.1(d)Compare & Arrange Integers

Example: Compare and Arrange The
Integers

-3, 4, 2, -5, 6, 0, -1

(a) In ascending order

(b) In descending order

1.2 Basic arithmetic operation involving
integers

Integers addition +( + ) = +
and subtraction -(- )=+
+( - ) = -
rules!! -(+)=-

(a) Addition

To add a positive integer, we count to the right on
the number line
To add a negative integer, we count to the left on
the number line

-+

-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6

Example 1: solve

3 + (-5) = 3 – 5
= -2

+

-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6

-

Example 2: solve

-3 + (+7) = +4

-

-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6

+

Example 3 : solve
-3 + (-4)

Solution:

-3 + (-4) = -3 -4
= -7

-

(b) Subtraction
To subtract a positive integer, we count to
the left on the number line
To subtract a negative integer, we count to
the right on the number line

subtract a positive integer subtract a negative integer

-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6

Example 1 : solve

5-8

Solution: -

Example 2 : solve

3 – (- 6 )

Solution:

3 – (- 6 ) = 3 + 6
=9

+

Let’s play

-9 -5 -4 -3 -2 -1 0
-5 -4 -3 -2 -1 0 1
-4 -3 -2 -1 0 1 2
-3 -2 -1 0 1 2 3
-2 -1 0 1 2 3 4
-1 0 1 2 3 4 5
0 12 3 4 5 6

Let’s play 6 54 3 2 1 0
5 4 3 2 1 0 -1
4 3 2 1 0 -1 -2
3 2 1 0 -1 -2 -3
2 1 0 -1 -2 -3 -4
1 0 -1 -2 -3 -4 -5
0 1 2 3 -4 -5 -6

Math Challenge !!

-4 1 21
-4 3 -3 (-4)

Aren’t integers
interesting?