How do you find HCF?

Answer 1

To find the HCF of a small number like 12 and 18:

you would write out the the common factors of 12 and 18

12 18

1 1

2 2

3 3

4 6

6

12

what is the biggest factor of them both?

Ans: 6

The HCF of 12 and 18=6

To find the HCF of a bigger number, for example 240 and 924:

you would write a list of all the prime factors for 240(factors that are prime numbers.)

you can do this using a factor tree

then do the same for 924

the answers are: 240: 2 x 2 x 2 x 2 x 3 x 5 924: 2 x 2 x 3 x 7 x 11in both 2, 2 and 3 repeat

so you multiple them together

2 x 2 x 3= 12

12 is the HCF of 240 and 924