To me, I have always had problems with struggling to find the GCF and the LCM. It seemed very easy to me at first but when we started to find the LCM when i was in middle school I struggled all the way up to college because I couldn't understand the the way my teachers taught me. But know after spending some time on it, I have learned an easier ways to find the GCF and the LCM in my math class. To start out we need to know what a prime factorization is. Prime Factorization is finding which prime numbers you need to multiply together to get the original number. A great website to look at examples is found here. Another easy way to find the prime factorization is to use a factor tree which takes the number and takes any two factors and then takes their factors leaving you at the bottom when you can factor no more the prime numbers, which when multipled together give you the original number. A great website to try different numbers using a factor tree is found here.
So GCF stands for Greatest Common Factor, and LCM stands for the Least Common Multiple. The Greatest Common Factor can be found between two numbers and it is the greatest whole number that divides evenly into each of the numbers.
Here is a video that helps you find the GCF.
Here is a video that helps you find the LCM.
To find the LCM-the least common multiple of two or more non-zero whole numbers is actually the smallest whole number that is divisible by each of the numbers. Listed here is a website that teaches you how to find the Least Common Multiple. Here is an example of finding the LCM for 3 and 4. The multiples of 3 are 0, 3, 6, 9, 12, 15, 18, 21 and 24 and the multiples of 4 are 0, 4, 8, 12, 16, 20 and 24. We look and see that the highlighted numbers are the ones that each 3 and 4 have in common, sinces we can not choose zero the next number that both have in common are 12 so the LCM of 3 and 4 would be 12
Here is a video that helps you find the GCF.
Here is a video that helps you find the LCM.
To find the LCM-the least common multiple of two or more non-zero whole numbers is actually the smallest whole number that is divisible by each of the numbers. Listed here is a website that teaches you how to find the Least Common Multiple. Here is an example of finding the LCM for 3 and 4. The multiples of 3 are 0, 3, 6, 9, 12, 15, 18, 21 and 24 and the multiples of 4 are 0, 4, 8, 12, 16, 20 and 24. We look and see that the highlighted numbers are the ones that each 3 and 4 have in common, sinces we can not choose zero the next number that both have in common are 12 so the LCM of 3 and 4 would be 12
your websites did give me a different point of view on finding the GCF, but i think the websites only downfall is the poor example it used. it didn't go in-depth enough, but it did lay a foundation in its second method of prime factorization.
ReplyDelete