Integers

1
Integers
S4
Integers Positive and Negative
Add /Sub using Thermometer
Add / Sub Integers Mathematically
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Multiplying dividing Integers
Negative Coordinate Grid
2
Starter Questions
S4
Q1. Calculate
Q2. How many euros do I get for 20 if exchange
rate is 1 ? 1.5
Q3. What is the time difference 0928 and 1050
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Q4. The answer to the question is 90. What is
the question.
3
Integers
S4
Learning Intention
Success Criteria

1. To be able to do add and subtract both positive
   and negative integers using a thermometer.

1. To understand how to add positive and
negative numbers using the thermometer as an aid.
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4
Integers
S4
Definition An INTEGER is a negative or
positive whole number, including 0.
e.g. -2, -1, 0, 5, 100
Note -2.5, -1.2, 23.5
Are NOT INTEGERS
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Write down 3 places where negative numbers are
used
Interpreting negative numbers
Ex1 Page 16 Round Class
5
Integers
S4
(a) 4oC up from 12 o C
8
6
12 4 16
4
(b) 8oC down from 10 o C
2
10 - 8 2
0
-2
(c) 3oC up from -2 o C
-4
-6
-2 3 1
-8
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(d) 6oC down from 2 o C
2 - 6 -4
6
Integers
S4
Now try Ex 2 Ch1 (page 19)
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7
Starter Questions
S4
Q1. Calculate
Q2. How many euros do I get for 10 if exchange
rate is 1 ? 1.4
Q3. What is the time difference 0945 and 2030
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Q4. The answer to the question is 30. What is
the question.
8
Integers
S4
Addition Subtraction
Learning Intention
Success Criteria

1. To be able to write down mathematically the
   addition and subtraction of both positive and
   negative integers.

1. To explain how to write down mathematically
addition and subtraction of negative integers.
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9
Integers
S4
(a) 12 4
16
8
6
4
Go up 4
Start at 12
2
0
-2
(b) 10 (-8)
2
-4
-6
-8
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Start at 10
Go down 8
(c) 7 - 10
-3
Start at 7
Go down 10
10
Integers
S4
Examples
Remember - - - -
-4
(1) 3 - 7
(2) 4 (-9)
-5
(3) -7 - 8
-15
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(4) -2 (-12)
-14
(5) -5 - 25
-30
(6) 8 (-9)
-1
11
Integers
S4
Now try Ex 3 Ch1 (page 20)
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12
Starter Questions
20o
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xo
xo
13
Integers
Multiplication Division
Learning Intention
Success Criteria
1. Understand how to multiply and divide
positive and negative integers.
1. Explain how to multiply and divide positive
and negative integers.
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14
With your partner can try and come up with the
rules for multiplying integers
(ve) x (ve) (ve) (-ve) x (ve)
(ve) (-ve) x (ve) (-ve) (ve) x (ve) (-ve)
Integers
Multiplication Division
Multiplying Integers
2
1 x (-2)
(-2) x (-1)
-2
-20
(-4) x 5
(- 2) x (-5)
10
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-9
(-3) x 3
(-5) x (-5)
25
Same signs positive answer Different signs
negative answer
32
(-4) x (-8)
5 x (-8)
-40
15
With your partner can try and come up with the
rules for multiplying integers
(ve) (ve) (ve) (-ve) (ve)
(ve) (-ve) (ve) (-ve) (ve) (ve) (-ve)
Integers
Multiplication Division
(-2) 1
(-2) (-1)
-2
2
4
20 (-5)
(- 20) (-5)
-4
Same signs positive answer Different signs
negative answer
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(-9) 3
-3
(-9) (-3)
3
5
(-25) 5
(-40) (-8)
-5
16
Same signs positive answer Different signs
negative answer
Remember BODMAS
Integers
S33
Multiplication
Multiplying Integers
1 (-2) x (-10)
21
28
3 (-5)2
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-1
8 (-3)2
5 x (-2)2 5 19
6
17
Remember BODMAS
Same signs positive answer Different signs
negative answer
Integers
S33
Division
Division Integers
1 (-20) (-10)
3
4
100 (-5)2
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96
100 - 36 (-3)2
-48 (6 - 2)2 5
2
18
Integers
Multiplication Division
Now try MIA Ex 4 Ch1 (page 21)
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19
Starter Questions
S4
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20
Coordinates
S4
Extending the Grid Negative Numbers
Learning Intention
Success Criteria

1. Identify main parts of coordinate grid.

1. To show how we can extend the coordinate
grid to include negative numbers.
2. Understand the negative grid both in y-axis
direction and x-axis direction.
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21
Coordinates
S4
Extending the Grid Negative Numbers
We can further extend the negative grid
Plot the point
y - axis
(-2,2)
3
x-coordinate is -2
2
1
y-coordinate is 2
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origin
0
-2
-3
2
4
-1
1
3
-4
x - axis
-1
(-4,-2)
-2
-3
x-coordinate is -4
y-coordinate is -2
Write down coordinates of the other points
22
Coordinates
S4
Extending the Grid
Now try Ex 5 Ch1 (page 23)
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