Download 1 - Stobies

Positive and Negative Numbers
The Number Line.
-7 -6 -5 -4 -3 -2 -1 0
1
2 3
4
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.
5
6 7
8
Adding and Subtracting.
Subtract
-7 -6 -5 -4 -3 -2 -1 0
1
2 3
4
5
6 7
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.
(3) Move 10 left.
(4) Now answer the question
6 – 10 = -4
8
Adding & Subtracting Example.
Add
-7 -6 -5 -4 -3 -2 -1 0
Now calculate:
1
2 3
4
5
-3 + 7 =
(1) At what number do you start? -3
(2) To add do you move left or right? right
(3) How many squares do you move?
(4) The answer to the sum
-3 + 7 = 4
is?
7
6 7
8
Adding & Subtracting Example.
-7 -6 -5 -4 -3 -2 -1 0
1
2 3
Calculate
–2–3=
At what number do you start?
How many steps do you move?
Now complete the sum :
– 2 – 3 = -5
4
5
6 7
8
What Goes In The Box ?
Complete the questions below yourself:
(1) 6 – 8 =
-2
(6) 7 – 12 = -5
(2) – 2 + 6 =
4
(7) – 7 + 12 = 5
(3) – 5 + 7 =
2
(8) – 6 + 6 = 0
(4) –4 + 8 =
4
(9) – 2 – 5 = -7
(5) –1 – 6 = -7
(10) – 2 + 7 – 8 = -3
What Goes In The Box ? 2
Complete these questions using a bigger number line if
required:
(1) 12 – 16 = -4
(6) 72 – 120 = - 48
(2) – 32 + 26 = -6
(7) – 34 + 52 = 18
(3) – 35 + 43 = 8
(8) – 36 + 26 = -10
(4) –14 +28 = 14
(9) – 42 – 57 = -99
(5) –18 – 52 = -70
(10) – 29 + 73 – 89 = -45
What goes In The Box ? 3
Work backwards here to work out the missing
numbers.
(1) – 6 + 18 = 12
(2) -13 + 10
= –3
(3) 12 – 34 = – 22
(4) -11 – 14
= – 25
(5) 22 – 39 = – 17