highest common factor

This is the name given to the highest number which divides exactly into two or more numbers.

For example:

• Factors of 16 are 1, 2, 4, 8 and 16

• Factors of 24 are 1, 2, 3, 4, 6, 8, 12 and 24

• Factors of 56 are 1, 2, 4, 7, 8, 14, 28 and 56.

By looking at these factors, we can see that 1, 2, 4 and 8 are the common factors of 16, 24 and 56. Therefore, the highest common factor is 8.

The acronym HCF is sometimes used.