Finding the GCF and LCM 

GCF 

To find the GCF, you need to divide both numbers and write the number that is being divided equals to the number of times the second number can go into the first number (how many times 180 can go into 378), then add the remainder.

GCF of 180 and 378:

 

Keep dividing until the remainder is 0. In this case, the equation left is 180 = 10(18) + 0, which means 18 is the GCF because 18 can go into 180 equally without a remainder.

LCM 

To find the LCM, you need to take both numbers and multiply them.

180 and 378

180(378) = 68 040

After you multiply both numbers, you then take the number and divide it by the GCF.

68 040/18    (18 is the GCF)

= 3 780

So the LCM of 180 and 378 is 3 780.

 

Between this method and prime factorization, I think prime factorization is better because it works for any amount of numbers given whereas this method only works with two numbers. Although, I would use this method if given two numbers because I find it quicker and easier for larger numbers.