Finding the combinations of numbers that multiply together to create a composite number.

**Prime Factorization**

**KWL**

KWL stands for what you

K

now, what you

W

ant to know, and what you have

L

earned.

Prime Factorization

The process of breaking any number into its smallest whole pieces or prime number factors.

Factor Trees

A factor tree is how we show the prime factors of a number.

You do

Create a factor tree in your spiral for the numbers 20 and 30.

Welcome! September 20, 2013

Objective: I will be able to create the prime factorization of a number using a factor tree.

Standard: 6.NS.4 Finding the greatest common factor.

You will need the following:

-Math Spiral Notebook

-3 Pencils

Pull out yesterday's homework, "Prime and Composite Numbers," and be prepared to grade it.

In your math spiral notebook, write a list of what you

K

now about prime factorization and factor trees.

Then underneath your list, write 1 question about what you

W

ant to know.

Ex:

a) 8 = 8 x 1

b) 8 = 4 x 2

c) 8 = 2 x 2 x 2

Which answer shows the Prime Factorization of 8?

36 = 1 x 36

or

2 x 18

or

3 x 12

or

4 x 9

or

6 x 6

20

/ \

4 5

/\ |

2 2 5

30

/ \

10 3

/\ |

5 2 3

20

/ \

(? x ?)

30

/ \

**

Once you have all prime numbers, you know you are done factoring.

**

Prime and Composite Review

Finish the sentence...

1. A prime number is a whole number greater than ___ that is divisible only by ___ and ______.

2. A _________ number is a whole number that is _________ by more than two numbers.

Label the prime and composite numbers...

12 7 8 19 23 25 3 1

KWL

Closure

: In your spiral, write a complete sentence that explains what you have

L

earned.

** Remember to include words like, "And," "Because," "But," and, "Or."

Homework

Complete the worksheet titled, "Prime Factorization and Factor Trees ."

It is due Monday!

It will be scored out of a possible 14 points.

Have a great weekend! :)

**Answers**

1. a) P b) C c) P

d) C e) C f) P

2. a) 16, 38, 156, 344

b) 21, 54, 225

c) 40, 88, 164

d) 60, 95, 120

e) 72, 90, 684,

f) 77, 105, 196, 1260

3. a-f) Any answers that have two PRIME numbers that ADD up to the answer.

4. a) 6, 8, 9, 10, 12, 14

b) 18, 20, 21, 22

c) 52, 54, 55, 56, 58

d) 81, 82, 84, 85, 86, 88, 90, 92, 94,

95, 96, 98, 99

e) 116, 118, 120, 123, 124

f) 152, 153, 154, 155, 156, 158, 159

5. 2, 3, 5, 7, 11, 13, 17, 19, 23, 29,

31, 37, 41, 43, 47

6. Four digit composite number minus a two digit prime number.

Factor

48

52