1. Chapter 4 Number Theory

2. 4.1 Divisibility

3. Terms
Factors
Divides, divisible, divisibility
Multiple

4. Example

5. Divisibility

6. Divisibility Determining divisibility by 2

7. Divisibility Determining divisibility by 5

8. Even and odd numbers What is an even number?
What are the properties of an even number?
How do you recognize an even number?

9. Even and odd numbers
Representing an even number generally.

10. Even and odd numbers What is an odd number? What are its properties?
How do you recognize an odd number?

11. Even and odd numbers
How can an odd number be represented generally?

12. Even and odd numbers
What kind of number do you get when you add two even numbers?
What kind of number do you get when you add two odd numbers?
What kind of number do you get when you add an even number and an odd number?

13. Even and odd numbers
What kind of a number do you get when you multiply two even numbers?
What kind of a number do you get when you multiply two odd numbers?

14. Even and odd numbers
What can you say about two numbers if their sum is even and their product is odd?
Why?

15. Even and odd numbers
The sum of three numbers is an even number. Does the product have to be an even number or an odd number or can it be either one?