1. How can you find the greatest common factor of two numbers?

2.  What is a factor? ◦ Number that divides evenly into another number  Greatest Common Factor ◦ The greatest of factors shared by two or more numbers

3.  Find the GCF of 24 and 40 ◦ List all of the factors for each number. ◦ Circle the common factors  Find the greatest common factor 24 = 40 =

4.  Find the GCF of 12 and 56 1256 2 6 28 2 3 14 GCF = 2 x 2 = 4

5.  Find the GCF of 32 and 90.  Find the GCF of 20 and 45.

9.  How can you find the GCF of two numbers? List the different methods and which one your prefer.

10. How can you find the least common multiple of two numbers?

11.  What is a common multiple? ◦ Multiples shared by 2 or more numbers  What is the least common multiple? ◦ The least of the common multiples

12.  Find the LCM of 4 and 6.  Find the LCM of 6 and 10.

13.  Find the LCM of 16 and 20 ◦ 1620 2 8 102 4 5 LCM = 2 x 2 x 4 x 5 = 80 You form and L!

14.  Find the LCM of 9 and 12.  Find the LCM of 28 and 36.

18.  How can you find the LCM of two numbers?  Which method do you prefer?

21. Why is finding the LCM important when adding and subtracting fractions?

22.  They all had the same denominator.  What happens if they don’t have the same denominator?  You have to find the Least Common Multiple or Least Common Denominator.

23. The LCD of 8 and 6 is 24, so rewrite each fraction to be out of 24.

27.  Why is the LCM so important to adding and subtracting fractions?