1. Please get out your Homework, and a pencil, and your notes journal. Please be ready as soon as the bell rings. If you have any questions please put them on a Sticky note and put it on my desk by the computer.

2. Number Theory Composite Number- A number that is divisible by more than just 1 and itself. – Ex: 6, 39, 42 Prime Number- A number that is divisible by only 1 and itself. – Ex: 2, 5, 17 Factors- Whole numbers that are multiplied together to get a product. – Ex: (1, 2, 3, 6 are factors of 6)

3. Prime Factorization Prime factorization- Is a number written as the product (multiplication) of only its prime factors. – 18 (2 ∙ 3 ∙ 3) or 2 ∙ 3² – 100 (2 ∙ 2 ∙ 5 ∙ 5) or 2² ∙ 5²

4. Factors A factor is a number that you multiply together to get another number. – The factors of 24 are: 1, 2, 3, 4, 6, 8, 12, 24 The greatest common factor (GCF)is the biggest factor at least two numbers have in common or the same. – The greatest common factor (GCF) of 15 and 20 is 5 because the factors of 15 are: 1, 3, 5, 15 and the factors of 20 are: 1, 2, 4, 5, 10, 20. The greatest factor they have in common is 5.

5. Multiples A multiple is when you count by a certain number. – The multiples of 4 are: 4, 8, 12, 16, 24, … The Least Common Multiple is the smallest multiple that at least two numbers have in common (the same) – The LCM of 4 and 6 is 12 because the multiples of 4 are: 4, 8, 12, 16, … and the multiples of 6 are: 6, 12, 18, 24 … so the smallest one in common is 12.