- The largest factor that is a factor of two or more integers or terms
- Example: 7 is the greatest common factor between 14 , 21, and 35
- Applications: simplifying fractions, factoring polynomials
- With respect to fractions, the GCF between the numerator and denominator is called the Greatest Common Divisor or GCD
- Methods of finding GCF between integers: List the factors of each integer, prime factorization of each integer