Prime Factorization

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Prime Factorization. 2-2. http://www.brainpop.com/math/numbersandoperations/factoring/. Brainpop - Factoring video .. Answer the questions. http://www.brainpop.com/math/numbersandoperations/factoring/ quiz/. Answers : C D B A A D C B C A. Factor. - PowerPoint PPT Presentation

Transcript of Prime Factorization

Get papers sit down

get out homework&quietly work on bellringer

Solve

-4^2 (-2)^3 (-3)^4

Solve

-4^2 (-2)^3 (-3)^4

-16 -8 81

Get papers sit down

get out homework&quietly work on bellringer

Solve

-2^2 (-2)^4 (-3)^3

Solve

-2^2 (-2)^4 (-3)^3

-4 16 -27

Prime Factorization

2-2

http://www.brainpop.com/math/numbersandoperations/

factoring/

Brainpop - Factoring video .. Answer the questions

http://www.brainpop.com/math/numbersandoperations/factoring/quiz/

Answers:

1. C2. D3. B4. A5. A6. D7. C8. B9. C10. A

Factor

The numbers that are multiplied to get a product

15 = 3 x 53 and 5 are factors of 15

2 x 9 = 182 & 9 are factors of

18

3 x 2 =63 & 2 are

factors of 6

Prime Number

is a counting number that only has two factors, itself and one.

One is not a prime

7 is a prime5 is a

prime

Composite Number

Counting numbers which have more than two factors (such as six, whose factors are 1, 2, 3 and 6)

One is not a composite

8 is a composite55 is a

composite

A Rhyme to Help Us Remember

Prime numberPrime numberWhat do you see?I see no other factorsExcept for one and me.

Composite numberComposite numberWhat do you see?I see at least three factorsIncluding one and me.

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All of the orange numbers on this chart are prime. Write them down. Refer to them so you don’t waste time trying to factor them.

Prime Factorization

When a composite number is written as a product of all of its prime factors

Using the Factor Tree

78 / \ / \ 2 x 39 / / \ / / \ 2 x 3 x 13

Let’s Try a Factor Tree!

84 / \

2 x 42 / / \ 2 x 2 x 21 / / / \ 2 x 2 3 x 7

Factor Trees do not look the same for the same number,

but the final answer is the same.

72 / \

8 x 9 / \ / \

2 x 4 x 3 x 3 / \ 2 x 2 x 2 x 3 x 3

72 / \

2 x 36 / / \ 2 x 2 x 18 / / / \ 2 x 2 x 2 x 9 / / / / \ 2 x 2 x 2 x 3 x 3

Greatest Common Factor

The largest common factor of 2 or more numbers

Use prime factorization or ladder to find GCF

GCF of 24 and 36Is 12

GCF of 72 and 84Is 12

Prime Factorization is helpful for finding greatest common factors.

72 / \

8 x 9 / \ / \

2 x 4 x 3 x 3 / \ 2 x 2 x 2 x 3 x 3

Take the common prime factors of each number and multiply to find the greatest common factor.

84 / \ 2 x 42

/ / \ 2 x 2 x 21 / / / \ 2 x 2 3 x 7

2 x 2 x 3 = 12

Least Common Multiple

The smallest product that both numbers have in common

LCM of 4 & 10 is 20

LCM of 5 & 7 Is 35

LCM of 12 & 15 Is 60

Use the Ladder for LCM, GCF and Simplifying Fractions WRITE the two

numbers on one line. DRAW THE L SHAPE DIVIDE out common

prime numbers starting with the smallest

722 84362 42183 21

6 7 LCM makes an L: LCM = 2 2 3 6 7 = 504

GCF = 2 2 3 = 12

8472 = 7

6GCF is down the left side:

Simplified fraction is on the bottom

Use the Ladder for LCM, GCF and Simplifying Fractions WRITE the two

numbers on one line. DRAW THE L SHAPE DIVIDE out common

prime numbers starting with the smallest

242 36122 18

63 92 3

LCM makes an L: LCM = 2 2 3 2 3 = 72

GCF = 2 2 3 = 12

3624 = 3

2GCF is down the left side:

Simplified fraction is on the bottom

Use the Ladder for LCM, GCF and Simplifying Fractions WRITE the two

numbers on one line. DRAW THE L SHAPE DIVIDE out common

prime numbers starting with the smallest

63 92 3

LCM makes an L: LCM = 3 2 3 = 18

GCF = 3

96 = 3

2GCF is down the left side:

Simplified fraction is on the bottom

Use the Ladder for LCM, GCF and Simplifying Fractions WRITE the two

numbers on one line. DRAW THE L SHAPE DIVIDE out common

prime numbers starting with the smallest

5 75 7

LCM makes an L: LCM = 5 x 7 = 35

GCF = 1

75 = 7

5GCF is down the left side:

Simplified fraction is on the bottom

1

HOMEWORK PG 77

4 – 40 evens only

8-16 use ladder26-32 use factor trees34-40 use ladder

method

HOMEWORK Ps 2-2 evens only

2-14 ladder20-26 factor tree use

exponents28-34 ladder

Interactive Practice for Factor Trees

1. Virtual Manipulatives2. Interactive Practice 13. Interactive Practice from MathPlayground.

com

The Birthday Cake Method

a.k.a. The Box MethodAn alternative to factor

treesA video from YouTube

Challenge Problem Use what you know about multiplying

whole numbers by variables and exponents to make a factor tree for the following monomial

45x3

45

x3

x x x59

33

A Random Thought about Prime Numbers

Brought to you from YouTube.com

Use the Ladder for LCM, GCF and Simplifying Fractions WRITE the two

numbers on one line. DRAW THE L SHAPE DIVIDE out common

prime numbers starting with the smallest

242 36122 18

63 92 3

LCM makes an L: LCM = 2 2 3 2 3 = 72

GCF = 2 2 3 = 12

3624 = 3

2GCF is down the left side:

Simplified fraction is on the bottom

Ch Test this Thursday

Big Rocks Quiz tomorrow – Decimal rules #1

Four Sight paper

HomeworkPractice sheet 2-1 evens

only