Download Prime Factorization

Prime Factorization
Now that you know about Multiples, LCM, Factors, and GCF, you can learn
about Prime Factorization!
Prime Factorization is similar to finding the Greatest Common Factor only
that you have to list all of the factors as PRIMES.
Remember, from Elementary school you learned what prime numbers
are. Primes only have 1 set of factors, 1 and itself!
So here is a beginning list of Primes: 2, 3, 5, 7, 11, 13*…..
All you have to do is divide the number only by Primes!
There are 2 methods you can use, Tree Method & Cake Method.
Let’s use 24 to find the Prime Factorization!
TREE
HINT: I can divide by 2
because the divisibility
rules say that if 24 ends
in an even number then I
can divide by 2!
24
2
12
Divide by 2 again
because 12 ends in 2!
2
6
2
3
Divide by 2 again because
6 is even! This time 3 is
prime so I can’t divide
anymore!
The Prime Factorization of 24 is 2 x 2 x 2 x 3
We like to shorten that and use exponents by writing it this way:
23 x 3
23 is a shortcut for writing 2 x 2 x 2 . The exponent stands for how many
times you will multiply the other number (or the base number).
CAKE Complete the cake by first starting at the bottom.
3. When you get the 1
at the top you make a
candle because 1 is not
a prime number.
1
3 3
2
6
2
12
2
24
2. Divide again by 2
because 12 is even and
make another layer of
cake.
1. Make a layer of cake
around your number.
Use the divisibility rules
and divide by 2.
The numbers on the outside of the cake become the Prime Factorization.
2 x 2 x 2 x 3 which is the same we got for the Tree Method!
We would still finish it by using exponents: 23 x 3