1. INTRODUCTION TO PRIME NUMBERS

2. A Reminder of Two Important Words Before we start to investigate Prime Numbers lets remind ourselves of Factors and Multiples 1) Factor – A Factor is the proper name for any number that will divide into another e.g. 6 is a factor of 36, 5 is a factor of 30 etc..... 2) Multiple – A Multiple is the proper name for the result of a multiplication e.g. 36 is a multiple of 6, 30 is a multiple of 5 etc........

3. Prime Numbers 1.Prime Numbers can only be divided by themselves and 1. 2. 1 itself is not a Prime Number 3. Any number can be broken down to a Product of Prime Factors (Prime Number Decomposition).. See later work

4. Prime Numbers Up To 100.... Remember ! You won’t find Prime Numbers in any times table. (1 is NOT Prime) 2, 3, 5, 7, 11.........are all Prime Numbers Can you find other Prime Numbers up to 100 ?

5. Prime Numbers Up To 100.... Remember ! You won’t find Prime Numbers in any times table. (1 is NOT Prime) 2, 3, 5, 7, 11.........are all Prime Numbers Can you find other Prime Numbers up to 100 ? 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 77, 79, 83, 89, 91, 97

6. How To Find A Prime Number.... A Simple Method 1)It must end in either 1, 3, 7 or 9 2)Find the square root of the number and make sure that the Primes below the square root won’t divide into it. e.g. Is 241 a prime number ? 1, 3, 7 or 9 OK ! 241 = 15.52.. x 15.52.. Primes less than 15 are 2, 3, 5, 7, 11, 13.. NONE divide 241, 241 is Prime !

7. Prime Number Exercise 1)Write down all the Prime Numbers up to 50 2)What is a i) Factor ii) Multiple 3) Are the following numbers Prime ? i) 119ii) 241 iii) 163 iv) 1872 Remember: Does it end in 1, 3, 7 or 9, Does it divide by primes below square root.....

8. Prime Number Exercise Answers 1)Write down all the Prime Numbers up to 50 2,3,5,7,11,13,17,19,23,29,31,37,41,43, 47 2)What is a i) Factor ii) Multiple i)A dividing number ii) result of multiplication 3)Are the following numbers Prime ? i) 119 no (7) ii) 241 yes iii) 163 yes iv) 1872 no Remember: Does it end in 1, 3, 7 or 9, Does it divide by primes below square root.....

9. Summary A Prime Number can only be divided by itself and 1. ANY whole number can be broken down into a multiplication (product) of Prime Factors.... see later work 1 is NOT a Prime Number Summary A Prime Number can only be divided by itself and 1. ANY whole number can be broken down into a multiplication (product) of Prime Factors.... see later work 1 is NOT a Prime Number