GCF Calculator

The factor which is common and largest between the two numbers is called the greatest common factor. It is the largest number which divides them giving the answer as the whole number. The greatest common factor (GCF) is also known as the highest common factor (HCF).

For Example

Olivia thinks of two numbers. The lowest common multiple (LCM) of the two numbers is 36. The highest common factor (HCF) of the two numbers is 3. Both numbers are less than 15. Write down two possible numbers that Olivia could be thinking of.