Prime Numbers

1. Prime Numbers Some Simple Tips and Reminders Powerpoint hosted on www.worldofteaching.com Please visit for 100’s more free powerpoints

2. Definitions • Even Numbers – Any number that can be divided by 2 • Odd Numbers – Any number that cannot be divided by 2 • Composite Number – An integer that can be divided by at least one other number (a factor) other than itself

3. Definitions • Prime Number – An integer whose only factors are 1 and itself. • Factor – a number that can divide another number without a remainder. • Prime Factors – an expression of numbers that divides another integer without a remainder where all the factors are prime.

4. What numbers are prime? • Let’s look at a number grid from 1 to 100 and see how they were discovered.

5. Here’s How You Do It Take out the number 1 because it is a special number

6. Here’s How You Do It Take out the number 1 because it is a special number

7. Here’s How You Do It Take out numbers that have a composite factor of 2

8. Here’s How You Do It Take out numbers that have a composite factor of 2

9. Here’s How You Do It Take out numbers that have a composite factor of 3

10. Here’s How You Do It Take out numbers that have a composite factor of 3

11. Here’s How You Do It Take out numbers that have a composite factor of 5

12. Here’s How You Do It Take out numbers that have a composite factor of 5

13. Here’s How You Do It Take out numbers that have a composite factor of 7

14. The PRIME Numbers! Take out numbers that have a composite factor of 7

15. How Do We Know They Are Prime? • Composite numbers can be placed into varying types of rectangles • Prime numbers cannot • Let’s look at that…

16. 15 24 Composite Numbers 6

17. 17 29 7 Prime Numbers

18. That’s It! • A prime number cannot be divided by anything other than 1 and itself.