List the factors of each number
Identify the common factors
Choose the highest common factor
If using prime factors, write each number as a product of primes
Find the common prime factors
Multiply the common prime factors
The result is the HCF
List the factors of each number
Identify the common factors
Choose the highest common factor
If using prime factors, write each number as a product of primes
Find the common prime factors
Multiply the common prime factors
The result is the HCF