1. Factors and Prime Factorization

2. Factors and Prime Factorization
Definitions:
Factors – Are whole numbers that are multiplied together to equal a product. A number is divisible by its factors.
Product – Is the answer to a multiplication problem.
Prime Numbers – Are whole numbers greater than 1 with exactly two factors, itself and 1.
Composite Numbers – Are numbers greater than 1 with more than two whole-number factors.
Prime Factorization – Is the form of a number written as the product of its prime factors.
2 • 3 = 6
Factors
Product

3. Factors and Prime Factorization
Finding Factors
Example:
List the Factors of the number 18.
1 and 18
2 and 9
3 and 6
Another way to write the factors of 18:

4. Factors and Prime Factorization
Finding Factors
List the factors of the numbers below.
1.) ) ) 72
Write the following numbers as a product in two different ways.
1.) ) 81

5. Factors and Prime Factorization
Writing Prime Factorizations
Example 1: 36
The prime factorization of 36 is 3 • 2 • 2 • 3 or 22 • 32.
Strategy:
1.) Choose any two factors of the number.
2.) Keep finding factors of the factors that you chose until each branch ends up at a prime number.

6. Factors and Prime Factorization
Writing Prime Factorizations
Example 2: 40
The prime factorization of 40 is 5 • 2 • 2 • 2 or 23 • 5.
Strategy:
1.) Choose any two factors of the number.
2.) Keep finding factors of the factors that you chose until each branch ends up at a prime number.

7. Factors and Prime Factorization
Writing Prime Factorizations
Write the prime factorization of each number using a factor tree.
1.) ) 100