What is the greatest common factor of 8?

Answer 1

There cannot be a greatest common factor (GCF) of just one number. To be common there need to be at least two numbers. If you find all the factors of two or more numbers, and you find some factors are the same ("common"), then the largest of those common factors is the Greatest Common Factor.

Answer 2

There's no such thing as a common factor of a single number. "Common" means "same for both." You need at least two numbers to find a GCF. For example, 17 is the GCF of 34, 51, and 102 because it is the largest number that is a factor common to all three numbers.

Answer 3

You would usually calculate the greatest common factor of two or more numbers; NOT of a single number.

Answer 4

32 and 40, among many others.