The largest number that is a factor or divisor or both of A & B
There are three methods:
- List the Factors
- Prime Factorization
- Linear (Cuisenaire rods)
- List the Factor
To get the GCF you list every multiple that would equal the two numbers
So we will find the GCF of (3,4)
Then circle every number that the two have in common
The GCF is the biggest number that they both have in common
Prime Factorization
Make a factor tree and get prime factors
(in this example we will be using 75 and 60)
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| Image Source Page: http://misterwhalen.blogspot.com/2008/10/factor-trees.html |
Next you find all the prime factors you can then make a venn diagram and use the prime numbers to find the common numbers
3x5=15
GCF(75,60) is 15
Linear (Cuisenaire Rods)
Each color has a certain number
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| Image Source Page: http://www.cet.ac.il/math-international/addition1.htm |
Find the GCF of (6,12)
whichever color rods can be used in both the least amount of times is the GCF of the two numbers
A cute little song about GCF & LCM
A fun little game
Erica, I think you did a good job showing all of the ways to find the GCF and the song was funny.
ReplyDeleteThe YouTube video was great! That is a great video for kids, I feel like when there is a song or a trick when learning something children or even adults catch on a lot faster. There is a lot of the songs for government classes about how bills are passed- the "I'm just a Bill" song; if there were more about math I feel like children would be able to remember more. I feel like math is hard for a lot of people so with a simple song and motions to go with it the children will connect with the application that needs to be done, so they will remember more of what they are suppose to do, because they are doing hands of verse only listening or watching what is being written on the board.
ReplyDeleteThanks for helping me study for the test!
ReplyDeleteI enjoyed the song, and think it's cute that the children sang the song instead of an adult or teacher. When children get help learning new information from other children, it seems to "stick" better than hearing it from other adults. The rectangular array pictures are a great way to find the GCF of two numbers. Having a visual sometimes helps to understand the steps to take to find the GCF rather than soley written explainations.
ReplyDeleteI love Factor Trees! This is what helped me in school, drive home that there are multiple numbers to come up with the answer. It also really helped when we started learning exponents best.
ReplyDeleteI think you did an awsome job at explaining and showing how to find the GCF. I love all the pictures because I am a visual learner. The video is also very cute and a good way to get your point across.
ReplyDeleteAll the ways to get GCF are so helpful. thank you for explaining it thoroughly. That song was super cute.
ReplyDeleteThe examples you used to show how to find the GCF were really helpful. I also thought the song was cute to figure out the difference between LCM and GCF.
ReplyDeleteLike I said in someone else's blog, I'm NOT a fan of factoring weird numbers. However, I do find the factor tree method very helpful. Now if I could just remember to multiply the common factors the tree produces. Hopefully the illustration you provided will help me, and especially now that I've written about it here!
ReplyDeleteErica, I loved the video. I found it pretty interesting and I actually got into it! It was a great way to figure out how to know the differences in the greatest common factor and the least common multiple! I also think that I could use that video in my classroom someday!
ReplyDelete