1. Greatest Common Factor

2. Vocabulary Product Product – An answer to a multiplication problem.
7 x 8 = 56
Product

3. Vocabulary
Factor – a number that is multiplied by another to give a product.
7 x 8 = 56
Factors

4. Vocabulary
Factor – a number that divides evenly into another.
56 ÷ 8 = 7
Factor

5. What are the factors?
6 x 7 = 42
6 & 7
7 x 9 = 63
7 & 9
8 x 6 = 48
8 & 6
4 & 9
4 x 9 = 36

6. 7 Vocabulary 7 is prime because the only numbers
Prime Number – a number that has only two factors, itself and 1. 7
7 is prime because the only numbers
that will divide into it evenly are 1 and 7.

7. Examples of Prime Numbers
2, 3, 5, 7, 11, 13, 17, 19
Special Note:
One is not a prime number.

8. 8 Vocabulary The factors of 8 are 1, 2, 4, 8
Composite number – a number that has more than two factors. 8
The factors of 8 are 1, 2, 4, 8

9. Examples of Composite Numbers
4, 6, 8, 9, 10, 12, 14, 15
Special Note:
Every whole number from 2 on
is either composite or prime.

10. Our Lonely 1 One is not a prime nor a composite number.
It is not prime
because it does
not have exactly
two different
factors.
It is not
composite
because it does
not have more
than 2 factors.
Special Note:
One is not a prime nor
a composite number.

11. How to Find
The Factors of a Number

12. Find all possible numbers that you can multiply together to get 12
Factors of 12
Find all possible numbers that you can multiply together to get 12
1 x 12
3 x 4
2 x 6
So, the factors of 12 are:
1, 2, 3, 4, 6, 12

13. Find all possible numbers that you can multiply together to get 24
Factors of 24
Find all possible numbers that you can multiply together to get 24
1 x 24
2 x 12
3 x 8
4 x 6
So, the factors of 24 are:
1, 2, 3, 4, 6, 8, 12, 24

14. Find all possible numbers that you can multiply together to get 36
Factors of 36
Find all possible numbers that you can multiply together to get 36
1 x 36
2 x 18
3 x 12
4 x 9
6 x 6
So, the factors of 36 are:
1, 2, 3, 4, 6, 9, 12, 18, 36

15. How to Find the Greatest Common Factor (GCF) of 2 Numbers

16. Biggest, largest, highest
Greatest
Common
Same number
Numbers that you multiply to get the product
Factor

17. Find the GCF of
12 and 24
12: 1, 2, 3, 4, 6, 12
24: 1, 2, 3, 4, 6, 8, 12, 24
GCF of 12 and 24 is 12

18. Find the GCF of
24 and 36
24: 1, 2, 3, 4, 6, 8, 12, 24
36: 1, 2, 3, 4, 6, 9, 12, 18,36
GCF of 24 and 36 is 12

19. Find the GCF of
12 and 16
12: 1, 2, 3, 4, 6, 12
16: 1, 2, 4, 8, 16
GCF of 12 and 16 is 4