1. Finding the Least Common Denominator to Add/Subtract Fractions

2. Make a ratio table for each fraction.1 6 3 4

3. Skip Count by 1 1 2 6 3 4

4. 1 2 3 6 3 4

5. 1 2 3 4 6 3 4

6. 1 2 3 4 5 6 3 4

7. Skip Count by 6 1 2 3 4 5 6 12 3 4

8. 1 2 3 4 5 6 12 18 3 4

9. 1 2 3 4 5 6 12 18 24 3 4

10. 1 2 3 4 5 6 12 18 24 30 3 4

11. 1 2 3 4 5 6 12 18 24 30
Skip Count by 3 3 6 4

12. 1 2 3 4 5 6 12 18 24 30 3 6 9 4

13. 1 2 3 4 5 6 12 18 24 30 3 6 9 12 4

14. 1 2 3 4 5 6 12 18 24 30
Skip Count by 4 3 6 9 12 4 8

15. 1 2 3 4 5 6 12 18 24 30 3 6 9 12 4 8

16. 1 2 3 4 5 6 12 18 24 30 3 6 9 12 4 8 16

17. Look at the 2nd row in each ratio table.1 2 3 4 5 6 12 18 24 30 3 6 9 12 4 8 16

18. Find the number each row has in common.1 2 3 4 5 6 12 18 24 30 3 6 9 12 4 8 16

19. These are the 2 fractions you will add.1 2 3 4 5 6 12 18 24 30 3 6 9 12 4 8 16

20. 1 2 3 4 5 6 12 18 24 30 3 6 9 12 4 8 16

21. Add the numerators 2 + 9
2 + 9 = 11

22. 2 12 + 9 12 Add the numerators 2 + 9 2 + 9 = 11
The denominator doesn’t change.

23. So….. =