1. Adding and Subtracting Mixed Numbers
Lesson 4-5

2. Review - Adding and Subtracting Fractions with Like Denominators
To add or subtract fractions with like denominators, add or subtract the numerators and write the result over the denominator. Simplify the fraction. 1 5 3 5 4 5
The denominator always stays the same. + =

3. Review - Adding and Subtracting Fractions with Unlike Denominators
Find the LCD, rename the fractions. Then add or subtract with like denominators. 7 8 5 6 8 6 2 4 3
2 x 4 x 3 = 24 LCD 21 24 20 24 1 24 20 7 8 21 5 6 = 24 24

4. Adding and Subtracting Mixed Numbers
First add or subtract the fractions. If necessary, rename the fractions with the LCD. Then add or subtract the whole numbers and simplify. 4 9 2 9 6 9 2 3 7 10 17 17 + = =

5. Try Some More 5 6 1 3 6 3 3 _ 8 2 = 2 1
LCD = 6 5 6 2 6 3 6 1 2 _ 8 2 6 6 = =

6. Try Some More 5 9 1 6 9 6 3 1 + 4 = 3 2
LCD = 18 10 18 3 18 13 18 + 1 4 5 =

7. Your Turn 1 12 7 12 2 3 + 3 14 17 = 7 10 3 5 1 10 - 9 4 5 =

8. Another Example 5 9 2 3 9 3 - 3 11 8 3 1
LCD = 9 5 9 6 9
Borrow from the whole number, to get a larger numerator. - 11 8 5 9 14
One whole is equal to 9 pieces.
Add to get the new numerator. 10 11 9

9. Another Example 8 9 2 3 14 = 10 - 2 8 9

10. Another way to look at it…1 4 3
3 wholes

11. Another way to look at it…1 4 3
5 pieces 2
wholes 1 4 5 4
Can be renamed as… 3 2

12. Another Example 3 8 7 8 10 8
Rename the improper fraction. + 2 5 7 = 1 2 8 1 4 2 8 8 10 8 8 1 + 7 = = 8 2