1. Investigating Factors of numbers

2. Investigate the factors of the following numbers
No.
Factors
Prime 1 11 2 12 3 13 4 14 5 15 6 16 7 17 8 18 9 19 10 20
Prime numbers are numbers that have exactly two different factors
( no more / no less) They have 1 and themselves

3. Prime numbers are numbers that have exactly two different factors
No.
Factors 1 11 2 12 3 13 4 14 5 15 6 16 7 17 8 18 9 19 10 20
Prime
Prime 1 No
1, 11
Yes
1, 2
Yes
1, 2, 3, 4, 6, 12 No
Prime numbers are numbers that have exactly two different factors
( no more / no less)
They have 1 and themselves
1, 3
Yes
Yes
1, 13
1, 2, 4
1, 2,7, 14 No No
1, 5
Yes
1, 3, 5, 15 No
1, 2, 3, 6 No
1, 2, 4,8,16 No
1, 7
Yes
1, 17
Yes
1, 2, 4, 8 No
1, 2, 3, 6, 9, 18 No
1, 3, 9 No
1, 19
Yes
1, 2, 5, 10 No
1, 2, 4, 5, 10, 20 No
Prime numbers are numbers that have exactly two different factors
( no more / no less) They have 1 and themselves

4. The first fifteen Prime numbers are
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47
Prime factors of a number
Find the factors of a number and say which are prime
e.g1 Find the prime factors of(i) 10 and (ii) 16 10
Prime factors of 10
are 2 and 5 16
`Prime factor of 16 is 2
1 x 10
1 x 16
2 x 5
2 x 8
4 x 4