The document provides instruction on teaching 4th grade students to add fractions with like and unlike denominators. It includes the learning objectives of students being able to add fractions with 80% accuracy when the denominators are the same or different. Examples are provided for finding the sum of fractions by keeping the denominator the same or finding the least common denominator.

1. Brandy Oliver

2.  Content Area: Mathematics
 Grade Level: 4th
 The purpose of this instructional PowerPoint is teach how to add
fractions with like denominators and different denominators.
 Learning Objective:
 Given two fraction with like denominators the student will be able to
add them and simplify the answer correctly with 80% accuracy.
 Given two fraction with unlike denominators the student will be able to
add them and simplify the answer correctly with 80% accuracy.
 Content Standard: GLE 0406.2.5 Add and subtract fractions with like
and unlike denominators.
 Accomplishment: SPI 0406.2.8 Add and subtract proper fractions with
like and unlike denominators and simplify the answer.

3. Quick Review
Remember: The denominator is the bottom number on
the fraction.
Denominator
Name the denominator in the following fractions:
1 7 4 1 2
2 8 4 3
2 3

4. Review
The numerator is the top number of a fraction.
Numerator
Name the numerator in the following fractions:
1 7 4 1 2
2 8 4 3
2 3

5. Adding Fractions with Like
Denominators
When you add fractions with like denominators keep
the denominator the same and add the numerators.
Example: 5
11
+ 4
11
= 9
11
Remember to simplify your answers.

6. Example
+ = Simplify the
answer.
1 1 2
4 4
4
Find the like
greatest
common factor
for 2 and 4.
2 2
4
÷ 2 = 1
2

7. Practice
Try this problem then compare with your partner.
+ =
4 5 9
11 11 11

8. Apply to Life
Work this problem out then compare your answer with
the neighbor in front of you.
1
Susan is cooking dinner. Her recipe calls for 3 of a cup of
water. She needs to double this recipe. How much
water does she need to use?
2/3 2/6

9. Try Again
Remember to keep the denominator the same.
Example:
1
1
4
+ 4 =
2
4

10. Correct!
1 1 2
3 + 3 = 3

11. Adding With Different
Denominators
If the fractions have different denominators, find the
least common denominator.
1
2 + 3 The least common
6 denominator is 6.
6÷ 2 = 3 3 The 3 will stay the
6 + 6
same because that
denominator is
already 6. Remember any
3 x 1= 3 number over its
so 1 will self equals 1.
+ = =1
2 3
become 6. 3 3 6
6 6 6

12. Apply to Life
If Alan filled up his fish tank 1 of the way full and
2 4
John filled up his 3 of the way full. If they poured all
of the water in one tank how full would it be?
Solve this problem individually.
3/7 3/12 7/12

13. Try Again
 You cannot just add straight across.
 Remember to find the least common denominator.
Example:
3
6 + 5
12
The lowest number that will these two numbers will go
into is 12 so 12 is the least common denominator.

14. Try Again
Once you find the least common denominator
remember that you have to multiply to find the
numerator.
Example:
3
4 + 1
2
6 4 Now you add the
8 numerators.
8

15. Correct!
The greatest common denominator is 12.
Since 12 will be the denominator. What will the numerators be?
3 and 4
So the fractions that we are adding will be
3 and 4
12 12
+ =
3 4 7
12 12 12

16. Apply to Life
Dawn used 1 of a gallon of water to wash her hands
2
and 1 of a gallon of water to brush her teeth. How
3
much water did she use in all?
1 and 1/6 gallons
2/5 of a gallon
7/6
1 1
2 + 3

17. Almost
 You are on the right track. Do not forget to change
improper fractions into mixed numbers.

18. Try Again
Remember to find to least common denominator.
Multiply to get the numerator then add.
Do not forget that the denominator stays the same.

19. Correct
The least common denominator of 2 and 3 is 6.
Multiply to find the numerator.
3 4 7 1
6 + 6 = 6 =1 6

20. A Few Reminders
 When the denominators are the same, just add the
numerators.
 When the denominators are different, find the least
common multiple.
 Simplify your answers.