Presents

What are integers?

0 1 2 3 4 5 6 7-1-2-3-4-5-6-7

positive numbersnegative numbers

Integers is the family name for positive and negative whole numbers.

Integers

Adding and Subtracting Integers °C1

098765

0

3

12

4

-1-2-3

-5-4

-3 + 5 =

-3

+5

2

2

Adding and Subtracting Integers °C1

098765

0

3

12

4

-1-2-3

-5-4

-3 + 5 =

-5+4

-1

2-5 + 4 =-1

Adding and Subtracting Integers °C1

098765

0

3

12

4

-1-2-3

-5-4

-3 + 5 =

-3

-8

5

2-5 + 4 =-1

5 - 8 =-3

Adding and Subtracting Integers °C1

098765

0

3

12

4

-1-2-3

-5-4

-3 + 5 =

-5

-4-1

2-5 + 4 =-1

5 - 8 =-3

-1 - 4 =-5

Adding and Subtracting Integers °C1

098765

0

3

12

4

-1-2-3

-5-4

-3 + 5 =

2

-6

82-5 + 4 =-1

5 - 8 =-3

-1 - 4 =-58 + (- 6) =2

Now try Exercise 2A

Subtracting negative numbers

5 – 3 =25 – 2 =35 – 1 =45 – 0 =55 – (-1) =5 – (-2) =

75 – (-3) =

8

Look at the numbers in green. What comes next??6

Can you think of an easy way

of remembering

this?

Subtracting negative numbers

4 (-5) =

Subtracting negative numbers

4 4 + 5 =(-5) = 9

Subtracting negative numbers

3 (-2) =

Subtracting negative numbers

3 3 + 2 =(-2) = 5

Subtracting negative numbers

-1 (-7) =

Subtracting negative numbers

-1 -1 + 7 =(-7) = 6

Now try Exercise 2B

Multiplying negative numbers

3 x 5 =15

3 x (-5) =-15

5 + 5 + 5 =15

(-5) + (-5) + (-5) =-15

Multiplying negative numbers

positive x negative = negative

K Hughes 2002