1. GCF - Greatest Common Factor
The GCF of two numbers is the greatest number that divides into both numbers evenly.
Ex: The GCF of 14 & 35 is 7, since 7 is the greatest number that goes into both 14 & 35 evenly

2. HOW TO FIND THE GCF
The key to determining the GCF is to identify Common Factors in Both Numbers and Multiplying them together.

3. COMMON FACTORS OF 225 & 30
225 30
3 • 5 • 2
5 • 5 • 3 • 3
THE COMMON FACTORS ARE 5 & 3

4. Finding Greatest Common Factor
Find GCF of 225 & 30

5. Finding Greatest Common Factor
Find GCF of 225 & 30
225
Complete Factor Tree for both numbers. 30
3 • 5 • 2
5 • 5 • 3 • 3

6. Finding Greatest Common Factor
Find GCF of 225 & 30
225
Complete Factor Tree for both numbers.
Identify Common Factors. 30
3 • 5 • 2
5 • 5 • 3 • 3
THE COMMON FACTORS ARE 5 & 3

7. Finding Greatest Common Factor
Find GCF of 225 & 30
225
Complete Factor Tree for both numbers.
Identify Common Factors.
Multiply Common Factors for GCF 30
3 • 5 • 2
5 • 5 • 3 • 3
THE COMMON FACTORS ARE 5 & 3
GCF = 5 • 3 = 15