1. Prime Factorization
Factor Trees

2. Find the prime factorization of 30
Draw two “branches” off of the number. 30

3. Find the prime factorization of 30
Write two numbers that are factors of 30.
*Remember: factors are the numbers multiplied together 30 6 5

4. Find the prime factorization of 30
Determine if the first number is prime or composite. (if don’t know definitions, click on the word.) 30 6 5

5. Prime The only factors of the integer are itself and one.
EX: *1
EX: * 1

6. Composite There are many factors for the integer.
EX: *24; 2*12; 3*8; 4*6
EX: *32; 2*16; 4*8

7. Find the prime factorization of 30
Notice the 6 is NOT PRIME. It is composite. So, Draw two “branches” off of the number and write two factors of six at the end of each branch. 30 6 5 2 3

8. Find the prime factorization of 30
The number 5 is prime, so there is no need to draw branches from it. Just circle the number. 30 6 5 2 3

9. Find the prime factorization of 30
The number 2 is prime, so there is no need to draw branches from it. Just circle the number. 30 6 5 2 3

10. Find the prime factorization of 30
The number 3 is prime, so there is no need to draw branches from it. Just circle the number. 30 6 5 2 3

11. Find the prime factorization of 30
Now that all numbers are prime, write the prime factorization of 30.
2 * 3 *5 30 6 5 2 3

12. Prime Factorization
The list of prime factors in numerical order as products of each other.

13. Find the prime factorization of 81
Draw two “branches” off of the number. 81

14. Find the prime factorization of 81
Write two numbers that are factors of 81. 81 9

15. Find the prime factorization of 81
Determine if the first number is prime or composite. 81 9 9

16. Find the prime factorization of 81
Notice the 9 is NOT PRIME. It is composite. So, Draw two “branches” off of the number and write two factors of nine at the end of each branch. 81 9 9 3 3

17. Find the prime factorization of 81
The number 3 is prime, circle the numbers. 81 9 9 3 3

18. Find the prime factorization of 81
The number 9 is not prime, so we need to draw branches of the number nine. 81 9 3

19. Find the prime factorization of 81
Now that all numbers are prime, write the prime factorization.
3 * 3 * 3 * 3 or 34 81 9 3

20. Find the prime factorization.34 75 28
120
225 16