Adding and Subtracting Simple Fractions and Mixed Numbers

1. Adding and Subtracting
Simple Fractions and
Mixed Numbers

2. Banana Bread Recipe
2 eggs
1 ¾ cup sifted flour
2 tsp baking powder
¼ tsp baking powder
1 cup mashed bananas (about 3 bananas)
½ tsp salt
⅓ cup vegetable oil
⅔ cup sugar

3. Which are similar fractions? Which are dissimilar?
Which are mixed numbers?
1 ¾
¼
½
⅓
⅔
2
5
6

4. Addition or Subtraction of Similar Fractions

5. Addition or Subtraction of Dissimilar Fractions
1. Find LCD of 5 and 10
LCD = 10

6. Addition or Subtraction of Dissimilar Fractions
1. Find LCD of 6 and 9
LCD = 18
*Always reduce your answer in it
simplest form

7. Addition or Subtraction of Dissimilar Fractions
1. Make equivalent fractions.
2. Subtract.
3. Reduce your answer in simplest
form if needed.
LCD

8. Addition or Subtraction of Dissimilar Fractions
1. Make equivalent fractions.
2. Subtract.
3. Reduce your answer in simplest
form if needed.
LCD

9. Practice 1
Find the sum. Express the answer in lowest terms.
1) ½ + ¼ =
2) ⅓ + ⅝ =
3) ¼ + ⅔ =
4) ⅙ + ½ =
5) 9 ½ + 2 ⅓ =

10. Practice 2
Find the difference. Express the answer in lowest terms.
1) ⅜ - ⅛ =
2) 14/15 - 4/15 =
3) 6/10 - 4/10 =
4) 8/12 - 6/12 =
5) 13/20 - 3/20 =

11. Adding/Subtracting Mixed Fractions
To add/subtract mixed fractions:
1. Add or subtract the whole number part.
2. If the fraction part share a common denominator, proceed
on adding or subtracting. If not, find their LCD to make
equivalent fractions.
3. If the answer is an improper form, reduce the fraction into
a mixed number.

12. Adding/Subtracting Mixed Fractions


13. Adding/Subtracting Mixed Fractions
Example 9:
and
+
1. Change mixed fractions
into improper fractions.
2. Make equivalent fractions
by finding their LCD.
3. The answer is an improper
fraction so, change it into a
mixed number.

14. Adding/Subtracting Mixed Fractions
Example 10:
and
-
1. Change mixed fractions
into improper fractions.
2. Make equivalent fractions
by finding their LCD.
3. The answer is in lowest
term.

15. Adding/Subtracting Fractions and Mixed Fractions
Example 11:
+

16. Adding/Subtracting Fractions and Mixed Fractions
Example 12:
+ +

17. Adding/Subtracting Fractions and Mixed Fractions
Example 13:
- -

18. Practice 3
Find the difference. Express the answer in lowest terms.
1) 14 ⅓ - 12 ⅖ =
2) 27 4/7 - 10 ¾ =
3) 15 ⅜ - 10 4/7 =
4) 5 - 8/5 =
5) 14 - 12 4/9 =

19. Summary
• To add/subtract similar fractions, simply combine the
numerators and copy the denominators.
• To add/subtract dissimilar fractions, make equivalent
fractions by finding the LCD of the fractions and then
proceed in adding or subtracting the fractions when they
are already similar.
• To add/subtract mixed fractions, change them into
improper fractions first then follow the rules for
adding/subtracting dissimilar fractions.
• Always reduce your answer in its simplest form.