Greatest Common Factor

The Greatest Common Factor (GCF) is the largest number that divides two or more numbers without leaving a remainder.

How to Find the GCF

1. List all factors of each number.
2. Identify the common factors.
3. Choose the largest common factor.

Example

For 12 and 18:

• Factors of 12: 1, 2, 3, 4, 6, 12
• Factors of 18: 1, 2, 3, 6, 9, 18
• GCF: 6