1. Today we will add and subtract simple fractions and mixed numbers and write them in simplest form. simple=most basic

2. We’ve learned how to add and subtract fractions and mixed numbers. We know that : 4 5 2 3 - 15 x 5 = x 3 = x 5 = x 3 = 10 12 2 15

3. Factor A number that divides evenly into another. Factors of 24 are 1,2, 3, 4, 6, 8, 12 and 24.

4. What are the factors of 9? Factors of 9 are 1, 3 and 9. Factors of 9 are 1, 3 and 9.

5. What are the factors of 10? Factors of 10 are 1, 5 and 10. Factors of 10 are 1, 5 and 10.

6. What are the factors of 7? Factors of 7 are 1 and 7.

7. What are the factors of 56? Factors of 56 are 1, 2, 4, 7, 8, 14, 28, and 56.

8. Common Factor When two numbers have the same factor it is called a common factor. A common factor of 12 and 6 is 3.

9. Name a Common Factor of 9 and 27? 1, 3, 9

10. Name a Common Factor of 4 and 8? 1, 2, 4

11. 1, 2, 4

12. Name a Common Factor of 15 and 30? 1, 3, 5, 15

13. Name a Common Factor of 12 and 48? 1, 2, 3, 4, 6, 12

14. Name a Common Factor of 9 and 21? 1, 3, 9,

15. Name a Common Factor of 10 and 25? 1, 5, 10

16. Name a Common Factor of 3 and 4? 1

17. Simplest Form When the only common factor of the numerator and denominator is 1, the fraction is in simplest form. 3 4 3 4 ÷ 1 1 =

18. Greatest Common Factor The greatest common factor is the largest factor between two numbers. 12 = 1, 2, 3, 4, 6, 12 18 = 1, 2, 3, 6, 9, 18

19. What is the Greatest Common Factor? 8 = 1, 2, 4, 8 12 = 1, 2, 3, 4, 6, 12

20. What is the Greatest Common Factor? 8 = 1, 2, 4, 8 14 = 1, 2, 7,14

21. What is the Greatest Common Factor? 6 = 1, 2, 3, 6 18 = 1, 2, 3, 6, 9, 15

22. What is the Greatest Common Factor? 6 = 1, 2, 3, 6 12 = 1, 2, 3, 4, 6, 12

23. What is the Greatest Common Factor? 8 = 1, 2, 4, 8 16 = 1, 2, 4, 8, 16

24. What is the Greatest Common Factor? 8 = 1, 2, 4, 8 10 = 1, 2, 5, 10

25. What is the Greatest Common Factor? 3 = 1, 3 6 = 1, 2, 3, 6

26. What is the Greatest Common Factor? 4 = 1, 2, 4 6 = 1, 2, 3, 6

27. What is the Greatest Common Factor? 7 = 1, 7, 21 = 1, 3, 7, 21

28. What is the Greatest Common Factor? 15 = 1, 3, 5, 15 24 = 1, 2, 3, 8, 12, 24

29. Shortcuts to reducing fractions If the fraction has any zeros, you can cross out any of the zeros. But you can only cross out any zeros if both the numerator and denominator have zeros. For example: 10 10100 = 1 10

30. How to Find the Simplest Form of a Fraction Find the greatest common factor of the numerator and the denominator and divide both the numerator and the denominator by that number. 12 18 2 3 ÷ 6 6 =

31. Simplify or Reduce This Fraction 12 18 2 3 ÷ 6 6 =

32. Simplify or Reduce This Fraction 9 21 3 7 ÷ 3 3 =

33. Simplify or Reduce This Fraction 12 20 3 5 ÷ 4 4 =

34. Simplify or Reduce This Fraction 10 15 2 3 ÷ 5 5 =

35. Simplify or Reduce This Fraction 10 16 5 8 ÷ 2 2 =

36. Simplify or Reduce This Fraction 12 16 3 4 ÷ 4 4 =

37. Simplify or Reduce This Fraction 3 12 1 4 ÷ 3 3 =

38. Simplify or Reduce This Fraction 2 8 1 4 ÷ 2 2 =

39. 2 4 1 2 ÷ 2 2 =

40. 6 9 2 3 ÷ 3 3 =

41. 6 8 3 4 ÷ 2 2 =

42. It’s important to know how to reduce fractions to their simplest form because… It will be on the CST’s! It is easier to work with larger parts of fractions that it is to work with smaller parts. Why else is it important?

43. What did you learn? What are factors? What are factors of 20 and 30? What is the greatest common factor? Reduce the fraction 20/100 to lowest terms? Are there any shortcuts to reducing fractions?