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This slide show covers adding two fractions with the same denominator, adding two fractions with one denominator that is a factor of the other, and, finally adding fractions with different denominators. There are a small number of questions for a class to complete as a 'check on learning' during the presentation. I'm assuming the class have access to a textbook or other collection of problems for use after the presentation.

This slideshare version is pretty dry. I usually include a visual 'starter' image of some kind, often a funny sign or joke or screen grab of a news article.

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• Great PP, check page 70, there is a miscalculation.

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2. 2. +
3. 3. + =
4. 4. + =
5. 5. + = 4 3
6. 6. + = 4 3 +
7. 7. + = 4 3 4 1 +
8. 8. + = 4 3 4 1 + =
9. 9. + = 4 3 4 1 + = 4 4
10. 10. + = 4 3 4 1 + = 4 4 1
11. 11. Same denominators: add the numerators!
12. 12. +
13. 13. + =
14. 14. + =
15. 15. + =
16. 16. + = 8 5
17. 17. + = 8 5 +
18. 18. + = 8 5 8 2 +
19. 19. + = 8 5 8 2 + =
20. 20. + = 8 5 8 2 + = 8 7
21. 21. + = 8 5 8 2 + = 8 7
22. 22. + = 8 5 4 1 + = 8 7
23. 23. If the denominators are different, find equivalent fractions, then add numerators
24. 24. +
25. 25. + 12 5 + 3 1
26. 26. + 12 5 + 3 1
27. 27. + + 12 5 + 3 1
28. 28. + + 12 5 + 3 1
29. 29. + + 12 5 + 3 1
30. 30. + + 12 5 + 3 1 12 5
31. 31. + + 12 5 + 3 1 12 5 +
32. 32. + + 12 5 + 3 1 12 5 + 12 4
33. 33. 12 5 + 12 4
34. 34. 12 5 + 12 4 =
35. 35. 12 5 + 12 4 12 9 =
36. 36. 12 5 + 12 4 12 9 = =
37. 37. 12 5 + 12 4 12 9 = = 4 3
38. 38. 1. Check denominators
39. 39. 1. Check denominators 2. Find equivalent fractions so denominators same
40. 40. 1. Check denominators 2. Find equivalent fractions so denominators same 3. Add numerators
41. 41. 1. Check denominators 2. Find equivalent fractions so denominators same 3. Add numerators 4. Cancel down if needed
42. 42. 1. Check denominators 2. Find equivalent fractions so denominators same 3. Add numerators 4. Cancel down if needed 5. Pull out the whole numbers if needed
44. 44. 10 3 5 2  4 3 8 7 
45. 45. 10 7 10 3 10 4 10 3 5 2  4 3 8 7 
46. 46. 10 7 10 3 10 4 10 3 5 2  8 5 1 8 13 8 6 8 7 4 3 8 7 
47. 47. Sometimes, you have to change both denominators…
48. 48. 5 4 4 3 
49. 49. 5 4 4 3 
50. 50. 5 4 4 3  You need a number that is a multiple of both 4 and 5…
51. 51. 5 4 4 3  = 20 ? 20 ? 
52. 52. 5 4 4 3  = 20 ? 20 ?  = 20 16 20 15 
53. 53. 5 4 4 3  = 20 ? 20 ?  = 20 16 20 15  = 20 31
54. 54. 5 4 4 3  = 20 ? 20 ?  = 20 16 20 15  = 20 31 = 20 11 1
55. 55. 1. Check denominators
56. 56. 1. Check denominators 2. Find ‘common denominator’ (LCM)
57. 57. 1. Check denominators 2. Find ‘common denominator’ (LCM) 3. Add numerators
58. 58. 1. Check denominators 2. Find ‘common denominator’ (LCM) 3. Add numerators 4. Cancel down if needed
59. 59. 1. Check denominators 2. Find ‘common denominator’ (LCM) 3. Add numerators 4. Cancel down if needed 5. Pull out the whole numbers if needed