Math6Qtr1Day2.ppt
- 2. Adding & Subtracting Fractions Teacher Notes: • Use this presentation to teach the steps for adding and subtracting fractions with unlike denominators. • It is assumed that students have a thorough understanding of the process for making equivalent fractions. • CLICK HERE to view a demonstration with opportunities for students to practice making equivalent fractions.
- 3. We need a common denominator to add these fractions.
- 4. 7, 14, 21, 28, 35… 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 We need a common denominator to add these fractions.
- 5. 7, 14, 21, 28, 35… 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 The first number IN COMMON that appears on both lists becomes the common denominator
- 6. x 2 x 2 X 7 x 7 7 6 7 + 6 = 13 13
- 7. We need a common denominator to add these fractions. 5, 10, 15, 20, 25, 30, 35, 40, 45 7, 14, 21, 28, 35, 42, 49, 56, 63
- 8. x 7 x 7 X 5 x 5 15 7 15 + 7 = 22 22
- 9. We need a common denominator to add these fractions. 7, 14, 21, 28, 35, 42, 49, 56, 63 8, 16, 24, 32, 40, 48, 56, 64, 72
- 10. x 7 x 7 x 8 x 8 32 21 32 + 21 = 53 53
- 11. We need a common denominator to add these fractions. 3, 6, 9, 12, 15, 18, 21, 24, 27 5, 10, 15, 20, 25, 30, 35, 40, 45
- 12. X 3 x 5 x 5 x 3 9 10 9 + 10 = 19 19
- 13. We need a common denominator to add these fractions. 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33 11, 22, 33, 44, 55, 66, 77…
- 14. x 11 x 11 X 3 x 3 15 22 15 + 22 = 37 37
- 15. We need a common denominator to add these fractions. 3, 6, 9, 12, 15, 18, 21, 24, 27 6, 12, 18, 24,…
- 16. x 1 x 1 X 2 x 2 4 1 4 + 1 = 5 5
- 17. We need a common denominator to add these fractions. 11, 22, 33, 44, 55, 66, 77… 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72
- 18. x 11 x 11 X 6 x 6 18 11 29 18 + 11 = 29
- 19. We need a common denominator to add these fractions.
- 20. We need a common denominator to add these fractions. 9, 18, 27, 36, 45, 54, 63, 72, 81 5, 10, 15, 20, 25, 30, 35, 40, 45
- 21. 9, 18, 27, 36, 45, 54, 63, 72, 81 5, 10, 15, 20, 25, 30, 35, 40, 45 The first number IN COMMON that appears on both lists becomes the common denominator
- 22. x 5 x 5 x9 x 9 36 35 36 + 35 = 71 71 36 + 35 = 71
- 23. We need a common denominator to add these fractions. 12, 24, 36, 48, 60, 72, 84, 96 8, 16, 24, 32, 40, 48, 56, 64, 72, 79, 80, 88, 96
- 24. x 3 x 3 x 2 x 2 19 10 + 9 = 19 9 10
- 25. 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 We need a common denominator to subtract a fraction from another. 11, 22, 33, 44, 55, 66, 77…
- 26. x 5 x 5 x 11 x 11 4 15 - 11 = 4 15 11
- 27. We need a common denominator to subtract one fraction from another. 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 … 10, 20, 30…
- 28. x 1 x 1 x 5 x 5 2 5 – 3 = 2 5 3
- 30. Answers On Next Slide • Each click on the next slide reveals an answer. • Check your papers. • If you discover an incorrect answer, be able to explain your mistake.