PRIME FACTORIZATIO

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Title: Prime Factorization

In this lesson, students will use a non-linear power point to learn how prime factorization.

Subject: Math, Grade Level 6th

Objectives: At the end of this lesson, students will be able to take a number and break it down into its prime components.

The Ohio Academic Content Standard covered in this lesson Number, Number Sense and Operations: Benchmark G, Indicator 2.

Procedures: Student will access power point and follow instructions on power point .

Evaluation:

Before: Work at board on prime numbers and factorizationDuring: Quiz embedded into power point.After: Quiz in class

Materials:

ComputerPaper (to complete work for quiz)Pencil (same)

Prime factorization is an important operation in math. We will be using it to help us find the least common multiple (LCM) when we are adding and subtracting fractions. When we find the LCM of two denominators, we will have found their least common denominator. This is only one of the uses prime factorization is helpful in.

In this presentation, we will be learning, and practicing, breaking numbers down into their prime factors.

Before we begin to learn Prime

Factorization let’s review some terms:

A prime number is a number that is only divisible by two numbers. Those two numbers are 1 and itself. For example:

3 is a prime number because the only two numbers that it can be divided by are 1 and 3.

6 is NOT a prime number because it can be divided by 1, 2, 3 and 6.

Factors are the numbers you multiply together to get another number. For example:

Since 2 x 3 = 6, 2 and 3 are factors of 6.

Prime Factorization is when you break a number down into its factors until all the factors are prime numbers. For example:

Since 2 and 3 are both prime numbers, they are the prime factors of 6.

Of course, finding the prime factors of 6 is easy.

What if you have a number like 36?

You create a factor tree for the number.

Like this:

36

18

9

33

2

2

2

2

2

Original Number

Divide by lowest prime number that

will work.

Divide 2nd number by lowest prime number that will

work.Divide 3rd number by lowest prime number that will

work.You stop when all the numbers have

become prime numbers. So the prime factors of 36 are: 2 x 2 x 3 x 3, or 22 x 32.

36

9

33

4

22

Original Number

Break into 2 factors that you know

Break the next set of numbers into factors that you

know.

Once again, stop when all the numbers have become prime numbers. So the

prime factors of 36 are: 2 x 2 x 3 x 3, or 22

x 32, the same as before.

There is a slightly different way to do the same thing. Some people

find that easier.

Now that you know the

method, let’s do a little practice!

Click here to start

What are the prime factors of 90?

2 x 3 x 5

2 x 3 x 3 x 5

6 x 3 x 5

Correct!

Click here to for next question

90

45

15

53

3

3

2

2

2

Sorry, click here to review how to break

a number into prime factors.

What are the prime factors of 96?

2 x 2 x 2 x 2 x 2 x 3

2 x 2 x 2 x 2 x 3

6 x 4 x 4

Correct!

Click here to for next question

96

12

4

22

3

3

8

4

22

2

2

What are the prime factors of 150?

6 x 25

2 x 15 x 5

2 x 3 x 5 x 5

Correct!

Click here to finish

150

75

25

55

3

3

2

2

2

Now that you’ve become a prime factorization wizard, here are a few other sites you might like to try:

• For a fun factor tree go to: http://www.mathplayground.com/factortrees.html• Here’s a fun “turkey shooting” game: http://www.toonuniversity.com/flash.asp?err=499&engine=14• For a few prime factorization facts and a table of all of the prime numbers up to 1000: http://www.factmonster.com/math/numbers/prime.html