HCF and LCM

Question 1

how do you find highest common factor?

Answer 1

common prime factors
multiply together

30: 5 x 3 x 2
50: 5 x 5 x 2
5 x 2 = 10 - HCF

Question 2

how do you find the lowest common factor?

Answer 2

common primes & leftovers
multiply together

30: 5 x 3 x 2
50: 5 x 5 x 2
5 x 2 x 3 x 5 = 150 - LCF