To understand how to use this method, it may be important to familiarize yourself with how to find the greatest common factor.
The greatest common factor between two numbers is the largest factor that both numbers are divisible by. Sometimes the greatest common factor is also referred to as the greatest common divisor (gcd),
or the highest common factor (hcf).
For example, find the GCF of the two numbers 12 and 16:
The factors for 12 are 1, 2, 3, 4, 6 and 12. These are factors of 12 because
12 is divisible by all of these numbers.
The factors for 16 are 1, 2, 4, 8, 16.
The two numbers (12 and 16) share common factors (1, 2, 4).
The greatest of these is 4 and that is the greatest common factor.
If using the equation
LCM = (a*b) / GCF(a and b).
Let's use the numbers 8 and 12, with 8 being variable (a) and 12 as variable (b). By using the CalcuNation GCF Calculator, we know that
the GCF of 8 and 12 is 4. So, our equation comes out to LCM = (8*12) / 4. This calculates out as LCM = 24.
There are other methods to find the least common multiple. While this calculator uses the greatest common factor, you can also use the listing multiples method.
The Listing Multiples method can get lengthy. You literally list out all of the multiples of each number until you find a matching number. The smallest number that matches on the list of multiples
is the least common multiple.
There is also the method of Prime Factorization. With this method, you list out all of the prime factors for each number. Then, list all of the prime factors, as many times as they occur for any given number. Then
multiply the list of factors together to find the LCM.
The LCM can also be found using the Venn Diagram method, a Cake/Ladder method or Division method.
