Maths - HCF, LCM

• The highest common factor of two numbers is the highest while number which divides into both.
• The lowest common multiple of two numbers is the smallest number that is a multiple of both
• To find the hcf or lcm of three numbers use prime factors to simplify them first then multiply all the primes together once
• LCM = product of all the primes raised to their greatest power
• HCF = product of all the primes raised to their least power
• To find the LCM of for e.g 12 and 18 you would write down the multiples of 12 and the multiples of 18, then match the lowest number that 8 in both multiplies.
• To find the HCF for e.g you want to find the HCF of 3 and 5 you would find the factors of five then the factors 3 and circle the highest number that are in both factors.
• All the information is on here to help you and there are examples also

  
• finding the highest common factor you find out what the factors are of both numbers then find the highest number that are in both factors.
• To find the LCM you would first write The multiples of both numbers and then discover the lowest number that are in both times tables
• the hcf can be found by finding the prime factors of two or more numbers and circling the highest number that appears in both sets of circles.
• to find the lcm you find the multiples of one number and the multiples of another number and find the smallest multiple that they have in common.
• The lcm can be found by writing down all the multiples of one number and then finding the smallest multiple that is divisible by both numbers.
• LCM is lowest common multiple
• HCF is highest common factor