This document provides information about adding and subtracting fractions, including: - Examples of adding fractions with unlike denominators and expressing the answer in lowest terms. - An activity that uses fraction strips to represent fractions and add them. - Sample fraction addition and subtraction problems for students to practice. - Questions about why knowing how to add and subtract fractions is important and what jobs may require working with fractions.

1. Mental Math
2
7
3
7
5
7
+ =
2
9
4
9
6
9
+ =
1
11
3
11
4
11
+ =

2. If you mix the mushrooms and onions together,
how many cups will there be in all? If you mix the
mushrooms and onions together, how many cups
will there be in all?
veggie pizza
INGREDIENTS:
𝟏
𝟒
cup mushrooms
𝟓
𝟖
cup onions
•
𝟏
𝟐
cup green peppers 1 cup artichokes
•
𝟏
𝟑
cup black olives
𝟏
𝟐
cup pizza sauce
•
𝟏
𝟒
cups cheese
• 1 pizza crust

3. Adding of Fractions

4. Learning Objective
LWBAT
• add unlike fractions and express the answer
in the lowest terms

5. Success Criteria
• All must be able to add like
fractions
• Most should be able to add
unlike fractions
• Some could solve real life
examples

6. Adding and Subtracting
Fractions
We need to make sure the denominator of both fractions is the
same before we add or subtract
1
2
3
4
+ =

7. Hands on Activity
Use the strips to show the fraction and then add
1
4
5
16
+ =
Clue : Think how many
1
16
strips
is equal to
1
4

8. If you mix the mushrooms and onions together,
how many cups will there be in all? If you mix the
mushrooms and onions together, how many cups
will there be in all?
veggie pizza
INGREDIENTS:
𝟏
𝟒
cup mushrooms
𝟓
𝟖
cup onions
•
𝟏
𝟐
cup green peppers 1 cup artichokes
•
𝟏
𝟑
cup black olives
𝟏
𝟐
cup pizza sauce
•
𝟏
𝟒
cups cheese
• 1 pizza crust

9. Home Assignment
The height of Burj Khalifa is about 830 metres. Suppose
you want design a building which will be taller than Burj
Khalifa by
𝟏
𝟏𝟎
km more than this. So what will be the
minimum height of that building? Give the answer in its
lowest term?

10. Hots
• Why is it important to know how to add and
subtract fractions? Can you think of situations
where you will need to add or subtract
fractions?
• What jobs do you think require you to work
with fractions?

12. Adding and Subtracting Fractions
a) 7/8
b) 8/12
c) 7/9
d) 7/10
e) 2/3
a) 11/12
b) 7/10
c) 8/15
d) 16/12 or 1 ¼
e) 11/24
a) 1 7/12
b) 1 5/56
c) 29/30
d) 29/52
e) 1 1/10
a) 5/8
b) 5/12
c) 1/3
d) 2/5
e) 1/2
a) 7/20
b) 8/21
c) 23/36
d) 9/22
e) 71/126
Click for
answers