Transcript prime factors

Prime Factors
Objective: To write a number as a product
of it’s prime factors.
Find the prime factors of 18.
To find prime
Split
18 into
a a
factors
draw
pairfactor
of factors.
tree.
18
2
9
Split 9 into a
pair of factors.
2 is a prime
3
3
number – so this
branch is finished
The prime factors of 18 are
2 2x x3 3x2 3
Maths @ Robert Smyth
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
Find the prime factors of 18.
18
3
Split 18 into a
pair of factors.
6
Split 6 into a
pair of factors.
3 is a prime
3
2
number – so this
branch is finished
The prime factors of 18 are
2 2x x3 3x2 3
Maths @ Robert Smyth
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
Find the prime factors of 20.
20
Split 20 into a
pair of factors.
10
2
2
5
Split 10 into a
pair of factors.
The prime factors of 20 are
2 2x2 2x x5 5
Maths @ Robert Smyth
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
Find the prime factors of 20.
20
5
4
2
2
Split 4 into a
pair of factors.
The prime factors of 20 are
2 2x2 2x x5 5
Maths @ Robert Smyth
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
Find the prime factors of 24.
24
12
2
6
2
2
Maths @ Robert Smyth
The prime factors of 24 are
2 x 223 xx 23 x 3
3
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
Find the prime factors of 24.
24
12
2
4
3
2
Maths @ Robert Smyth
The prime factors of 24 are
2 x 223 xx 23 x 3
2
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
Find the prime factors of 24.
24
8
3
4
2
2
Maths @ Robert Smyth
The prime factors of 24 are
2 x 223 xx 23 x 3
2
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
Find the prime factors of 24.
24
6
4
2
2
2
The prime factors of 24 are
2 x 223 xx 23 x 3
Maths @ Robert Smyth
3
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
Find the prime factors of these numbers:
12
16
30
22
28
64
100
125
240
144
Remember to find
prime factors you
draw a factor
tree!
Maths @ Robert Smyth
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
12
12
6
2
2
4
3
3
2
2
The prime factors of 12 are 2x2x3 or 22 x 3
Maths @ Robert Smyth
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
16
16
8
2
2
2
4
2
4
4
2
2
2
The prime factors of 16 are 2x2x2x2 or 24
Maths @ Robert Smyth
2
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
30
2
30
15
3
6
5
5
2
The prime factors of 30 are 2 x 3 x 5
Maths @ Robert Smyth
3
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
22
2
11
The prime factors of 22 are 2 x 11
Maths @ Robert Smyth
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
28
2
28
14
2
4
7
2
7
2
The prime factors of 28 are 2x2x7 or 22 x 7
Maths @ Robert Smyth
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
64
8
8
2
2
4
2
2
4
2
2
The prime factors of 64 are 2x2x2x2x2x2 or 26
Maths @ Robert Smyth
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
100
5
20
5
4
2
2
The prime factors of 100 are 2x2x5x5 or 22 x 52
Maths @ Robert Smyth
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
125
5
25
5
5
The prime factors of 125 are 5x5x5 or 53
Maths @ Robert Smyth
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
240
10
24
4
2
2
6
2
2
5
3
The prime factors of 240 are 24 x 3 x 5
Maths @ Robert Smyth
Prime Factors
Objective: To write a number as a product
of it’s prime factors.
144
12
12
3
3
4
2
2
4
2
2
The prime factors of 144 are 24 x 32
Maths @ Robert Smyth