Download Prime factorization

PRIME
FACTORIZATION
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 factorization
During: Quiz embedded into power point.
After: Quiz in class
Materials:
Computer
Paper (to complete work for quiz)
Pencil (same)
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:
of
Since 2 and 3 are both prime numbers, they are the prime factors
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
2
2
2
Original Number
Divide by lowest
prime number that
will work.
Divide 2nd number by
lowest prime number
that will work.
18
2
2
9
3
3
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.
There is a slightly different way to do
the same thing. Some people find
that easier.
36
Original Number
4
2
Break into 2 factors
that you know
9
2
3
3
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.
Now that you
know the
method, let’s do a
little practice!
Click here to start
What are the prime
factors of 90?
2x3x5
2x3x3x5
6x3x5
Correct!
90
2
45
2
3
2
3
15
3
Click here to for next question
5
Sorry, click here to
review how to break a
number into prime
factors.
What are the prime
factors of 96?
2x2x2x2x2x3
2x2x2x2x3
6x4x4
Correct!
96
8
12
2
2
4
2
3
2
3
4
2
Click here to for next question
2
What are the prime
factors of 150?
6 x 25
2 x 15 x 5
2x3x5x5
Correct!
150
2
75
2
3
2
3
25
5
Click here to finish
5
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