1. Greatest Common Factor
GCF

2. Greatest Common Factor (GCF)
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Greatest Common Factor (GCF)
1. Greatest Common Factor by Khan Academy
(6:19 min)
* This website provides practice problems!
2. Greatest Common Factor by Anywhere Math -- Two methods given
(6:53 min)
3. Greatest Common Factor cartoon
(3:26 min)
4. Greatest Common Factor song
(1:33 min)
5. Greatest Common Factor trick – fast mental math!
(8:10 min)
View each video link as a review of the lesson. The #2 link with the smiley face is the one shown in class.

3. Work these problems before checking on next slide.
PRACTICE PROBLEMS
Find the GCF of the numbers using lists of factors.
, , , 28, 49
Find the GCF of the numbers using prime factorizations.
, , , 75, 120
Work these problems before checking on next slide.

4. ANSWERS for PRACTICE PROBLEMS
Find the GCF of the numbers using lists of factors.
, , , 28, 49
GCF = 4 GCF = 18 GCF = 7
Find the GCF of the numbers using prime factorizations.
, , , 75, 120
GCF = 5 GCF = 2 GCF = 5

5. https://www.youtube.com/watch?v=3W8SeYgZcMo (9:13 min)
Math Journal Activity
On notebook paper copy the two methods listed on textbook page 20 – Method 1 and Method 2.
Place this page into your binder – behind “Math Journal” divider.
Note: On textbook page 21 Method 3 is shown (Ladder Method). See this link to learn it and decide whether or not you prefer to use it.
(5:49 min)
(9:13 min)

6. Today we learned…
…how to identify factors of a positive integer, common factors, and the greatest common factor of a set of positive integers;

7. Your teacher will tell you which of these two assignments to complete.
THIS
THAT or
Your teacher will tell you which of these two assignments to complete.