The highest common factor (HCF) of two or more numbers is the largest number that is a common factor of the numbers. To find it, write down the numbers as their prime factors. Then choose those factors that appear in all of the numbers.
Let’s look at some examples.
Find the HCF of the numbers 15, 24 and 30.
Find the HCF of the numbers 16, 24, 72 and 80.
Find the HCF of 1245 and 3000.
Find the HCF of 210, 315, and 650.