Download c) Prime Factorization, Make a List

copyright©amberpasillas2010
Prime NumbersA Prime number is a whole number with
only 2 factors, one and itself.
Example: 2, 3, 5, 7, 11, 13, 17…
Composite NumbersA Composite number is a number that
has more than two factors.
Example: 4, 6, 8, 9, 10, 12, 14, 15…
copyright©amberpasillas2010
Composite Number Composite numbers can be written as
the product of prime numbers. This is
called:
Prime Factorization Prime Factorization is the unique set of
prime numbers whose product equals a
given number.
copyright©amberpasillas2010
Prime Factorization is when you write a
number as the product of prime numbers.
Circle the
prime
numbers
 Factor
36
2
18
2 9
3
3
36  2  2  3  3
2
2
36  2  3
copyright©amberpasillas2010
Tree
Write the prime factorization of the number 24.
24
24
Circle
4 6
the prime 2 12
numbers
2 6
2 2 2 3
3
3 23  3
2 3
Notice you get the same answer doing it two
different ways! No matter how your start, you
will get the same answer!
2
That is why prime factorization is so unique!
copyright©amberpasillas2010
96
2
48
6
8
2 3 2 4
2 2
96  2  2  2  2  2  3
5
96  2  3
Notice we put them in order from least to greatest
copyright©amberpasillas2010
240
2
120
2
60
2 30
2 15
3 5
240  2  2  2  2  3  5
4
240  2  3  5
copyright©amberpasillas2010
1)
Try these!
80
2
2)
40
2
20
2
2
300
150
75
2
10
3
5
2
80  2  5
4
copyright©amberpasillas2010
25
5
5
300  2  3  5
2
2
9ab
9 ab
3 3 a b
9ab  3  3  a  b
Factor Form
copyright©amberpasillas2010
6m
6
2
m
2
2 3 mm
6m  2  3  m  m
2
Factor Form
copyright©amberpasillas2010
Factor - A whole number or variable expression
that divides evenly into a given whole
number or variable expression.
List all the positive factors of the following.
20
40
Why do you
1 20
1 40
think I always
2 20
Make 2 10
start with one?
4
5
4
10
a list!
5 8
copyright©amberpasillas2010
Making a list can be helpful to keep track of data
and to spot any missing data.
To find factors of a number make a list starting
with the lowest possible factor which is 1.
We start with 1 and work our way up. We know
we didn’t miss any factors because our list is
organized.
copyright©amberpasillas2010
60
1 60
2 30
3 20
4 15
5 12
6 10
copyright©amberpasillas2010
48
1 48
2 24
3 16
4 12
6 8
copyright©amberpasillas2010
84
1 84
2 42
3 28
4 21
6 14
7 12
copyright©amberpasillas2010
1) Find all the factors
2) Write the prime factorization.
3) Tell whether the number is prime or composite.
1) 124
1 124
2 62
4 31
1, 2, 4, 31,
62, 124
2) 124
2
3) 124
composite
62
2
31
2  31
2
copyright©amberpasillas2010
1) Find all the factors.
2) Write the prime factorization.
3) Tell whether the number is prime or composite.
1) 97
1 97
2) 97
97
1, 97
copyright©amberpasillas2010
3) 97
prime
Take Out Your Study Guide!!!
copyright©amberpasillas2010
#5
Prime Factorization is when you write a
number as the product of prime numbers.
36
Circle the
prime
numbers
2
 Factor Tree
18
2 9
3
3
36  2  2  3  3
2
2
36  2  3
copyright©amberpasillas2010
#6
Make A List
Making a list can be helpful to keep track of
data and to spot any missing data.
To make a list start with the lowest possible
factor which is 1.
Factors of 36
1 x 36
2 x 18
3 x 12
4x9
6x6
We know we
didn’t miss any
Factors because
our list is
ORGANIZED!
copyright©amberpasillas2010
Factors of 24
1 x 24
2 x 12
3x8
4x6