1. Factor Tree’s and Prime Factorization Section 4-2

2. Bell Ringer # Prime or composite? 1) 19 2) 82 3) 57 4) 85 5) 101 6) 121

3. Vocabulary Factor: Whole numbers that are multiplied to find a product are called factors. Prime Factorization: The prime factorization of a number is that number written as a product of prime factors.

4. Finding factors To find the factors of a number. Simply list the two numbers that when multiplied together, equal that number

5. Example 1 Find all the factors of 18 1 * 18 = 18 2 * 9 = 18 3 * 6 = 18 So the factors of 18 are 1, 2, 3, 6, 9, 18.

6. Example 2 Find all the factors of 13 1 * 13 = 13 Nothing else gets you 13, so the factors of 13 are just 1 and 13 because 13 is a prime number.

7. Example 3 Find all the factors of 24

8. On your own Find all the factors of 16.

9. Factor Trees Factor trees are something we use to help us find the prime factorization of a number.

10. Example 4 36 36

11. Example 5 64 64

12. Example 6 54 54

13. Lesson quiz Find all the factors of 21 Find the prime factorization of 24