1) The document provides instructions and examples for adding and subtracting like fractions. It explains that to add or subtract like fractions, you add or subtract the numerators and write the result over the common denominator. 2) Several examples are worked through step-by-step to demonstrate how to add and subtract fractions. Questions are also provided for additional practice. 3) The examples and practice problems help teach the key concepts of adding and subtracting like fractions by combining numerators over a common denominator.

1. Course 2, Lesson 4-3
Replace each with <, >, or = to make a true statement. Use a
number line if necessary.
1. 2.
3. 4.
List each set of numbers in order from least to greatest.
5. 0.75, , 65% 6. −3.55, −3.46,
7. In one litter of kittens, 2 out of 5 were male. In a second litter, 4 out
of 6 were male. Which litter had the greater percent of male
kittens?

4
7
7
16

2
3
3
13
4
1
13
4
1
5

6
2
16
2
3

32
8
27
3
50


2. Course 2, Lesson 4-3
ANSWERS
1. >
2. <
3. >
4. =
5. 65%, , 0.75
6. –3.55, , –3.46
7. Litter 2
2
3
27
3
50


3. WHAT happens when you add,
subtract, multiply, and divide
fractions?
The Number System
Course 2, Lesson 4-3

4. Course 2, Lesson 4-3 Common Core State Standards © Copyright 2010. National Governors Association Center for Best Practices and Council of
Chief State School Officers. All rights reserved.
The Number System
• 7.NS.1
Apply and extend previous understandings of addition and subtraction to
add and subtract rational numbers; represent addition and subtraction on
a horizontal or vertical number line diagram.
• 7.NS.1c
Understand subtraction of rational numbers as adding the additive
inverse, p – q = p + (–q). Show that the distance between two rational
numbers on the number line is the absolute value of their difference, and
apply this principle in real-world contexts.
• 7.NS.1d
Apply properties of operations as strategies to add and subtract rational
numbers.
• 7.NS.3
Solve real-world and mathematical problems involving the four operations
with rational numbers.

5. The Number System
• 7.EE.3 Solve multi-step real-life and mathematical problems posed
with positive and negative rational numbers in any form (whole
numbers, fractions, and decimals), using tools strategically. Apply
properties of operations to calculate with numbers in any form; convert
between forms as appropriate; and assess the reasonableness of
answers using mental computation and estimation strategies.
Mathematical Practices
1 Make sense of problems and persevere in solving them.
3 Construct viable arguments and critique the reasoning of others.
4 Model with mathematics.
7 Look for and make use of structure.
Course 2, Lesson 4-3 Common Core State Standards © Copyright 2010. National Governors Association Center for Best Practices and Council of
Chief State School Officers. All rights reserved.

6. • To add like fractions
• To subtract like fractions
Course 2, Lesson 4-3
The Number System

7. Course 2, Lesson 4-3
The Number System
• like fractions
11 4and
12 12
2 1and
3 3

8. Course 2, Lesson 4-3
The Number System
Words To add or subtract like fractions, add or subtract the
numerators and write the result over the denominator.
Examples Numbers Algebra
5 2 5 2 7
or
10 10 10 10

 
11 4 11 4 7
or
12 12 12 12

 
, where 0
a b a b
c
c c c

  
, where 0
a b a b
c
c c c

  

9. 1
Need Another Example?
2
3
Step-by-Step Example
1. Add + . Write in simplest form.
Add the numerators.
Simplify.

10. Answer
Need Another Example?
1
Find + . Write in simplest form.

11. 1
Need Another Example?
2
3
Step-by-Step Example
2. Add – + – . Write in simplest form.
Add the numerators.
Use the rules for adding integers.

12. Answer
Need Another Example?
Find – + – . Write in simplest form.

13. 1
Need Another Example?
2
3
4
Step-by-Step Example
3.
Commutative Property of Addition
Associative Property of Addition
Simplify.
So, Sofia and Jack ate 1 pizzas altogether.
Sofia ate of a cheese pizza. Jack ate of a cheese pizza and
of a pepperoni pizza. How much pizza did Sofia and Jack eat
altogether?

14. Answer
Need Another Example?
On Monday, Kieffer worked on a project for of an hour. On
Tuesday, he worked on it for of an hour and on Wednesday he
worked for of an hour. How much time did he spend working on
his project?

15. 1
Need Another Example?
2
3
Step-by-Step Example
4. Find – – .
Add the numerators.
= – or –1 Simplify.

16. Answer
Need Another Example?
Find – – . Write in simplest form.

17. 1
Need Another Example?
2
3
Step-by-Step Example
5. Find – .
Simplify.
Subtract the numerators.
= – or –
=

18. Answer
Need Another Example?
Find – . Write in simplest form.

19. 1
Need Another Example?
2
3
Step-by-Step Example
6. About of the population of the United States lives
in Florida. Another lives in Ohio. About what fraction
more of the U.S. population lives in Florida than in Ohio?
Simplify.
Subtract the numerators.
= or
=
About more of the U.S. population lives in Florida than
in Ohio.

20. Answer
Need Another Example?
A picture mounted on art board is inch thick.
The frame for the picture is inch thick. How
much thicker than the picture is the frame?

21. How did what you learned
today help you answer the
WHAT happens when you add,
subtract, multiply, and divide fractions?
Course 2, Lesson 4-3
The Number System

22. How did what you learned
today help you answer the
WHAT happens when you add,
subtract, multiply, and divide fractions?
Course 2, Lesson 4-3
The Number System
Sample answer:
• When you add or subtract like fractions, add or
subtract the numerators. Then, write the result over the
denominator.

23. The next lesson is about
adding and subtracting
fractions with unlike
denominators. How do you
think what you learned in
this lesson will connect
with the next lesson?
Course 2, Lesson 4-3
Ratios and Proportional RelationshipsThe Number System