The Number Line.

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Look at the number line above.

What numbers go before the zero?

We are now going to use the number line to carry out some calculations.

Positive and Negative Numbers

Adding and Subtracting.

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We are going to use the number line above to calculate the sum below:

6 – 10 =(1) Start at the number 6

(2) To subtract go left from 6.

Subtract

(3) Move 10 left.

(4) Now answer the question

6 – 10 = -4

Adding & Subtracting Example.

0 1 2 3 4 5 6 7 8-1-2-3-4-5-6-7Now calculate:

-3 + 7 =

(1) At what number do you start? -3

(2) To add do you move left or right?

Add

right

(3) How many squares do you move? 7

(4) The answer to the sum

-3 + 7 = is?4

Adding & Subtracting Example.

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Calculate

– 2 – 3 =

At what number do you start?

How many steps do you move?

Now complete the sum :

– 2 – 3 = -5

What Goes In The Box ?Complete the questions below yourself:

(1) 6 – 8 =

(2) – 2 + 6 =

(3) – 5 + 7 =

(4) –4 + 8 =

(5) –1 – 6 =

(6) 7 – 12 =

(7) – 7 + 12 =

(8) – 6 + 6 =

(9) – 2 – 5 =

(10) – 2 + 7 – 8 =

-2

4

2

4

-7

-5

5

0

-7

-3

What Goes In The Box ? 2Complete these questions using a bigger number line if required:

(1) 12 – 16 =

(2) – 32 + 26 =

(3) – 35 + 43 =

(4) –14 +28 =

(5) –18 – 52 =

(6) 72 – 120 =

(7) – 34 + 52 =

(8) – 36 + 26 =

(9) – 42 – 57 =

(10) – 29 + 73 – 89 =

-4

-6

8

14

- 48

18

-10

-99

-45-70

What goes In The Box ? 3Work backwards here to work out the missing numbers.

(1) – 6 + = 12

(2) + 10 = – 3

(3) 12 – = – 22

(4) – 14 = – 25

(5) 22 – = – 17

18

-13

34

-11

39