21st Century Lessons

Combining Like Terms

1

Warm UpOBJECTIVE: Students will be able to determine if expressions are equivalent by combining like terms.Language Objective: Students will be able to explain in words how to combine like terms.

Agenda

2

True or False? Explain your answer.

a. b. c. d.

True

True

True

False

Agenda:

1) Warm Up 2) Launch

3) Explore

4) Summary

5) Practice6) Assessment

3

True or False?- IndividualWhat is the Area?- Whole Class

No Tiles, Vocabulary, Process,Quick Check- Partners, Whole Class

Using Tiles- Partners

Exit Slip- IndividualPartners

OBJECTIVE: Students will be able to determine if expressions are equivalent by combining like terms.Language Objective: Students will be able to explain in words how to combine like terms.

5 minutes

5 minutes

5 minutes

17 minutes18 minutes

15 minutes

Launch- What is the Area?

Agenda

4

What is the area of the rectangle?

x

4 3

x

4 3

x

7

x

4 3

x 4x 3x

Area = 4x + 3x

+

7x

Area = 7x

Explore- Using Tiles

Agenda

5

Think back to the warm up .

x x x

Can we represent 3x another way using tiles?

So, how many tiles would we need?

+

Let each x represent a red tile.

xx x

We just combined all the x’s!

Definition

7

Explore- Using Tiles

Using your tiles, what would you get

Agenda

x x x x x x+

xxxxxx

if you combined 2x + 4x?

Is this the only way to show 6x?

Now combine!

8

Explore- Using Tiles

Agenda

x x x x x x+

xxxxxx

Is this the only way to show 6x?

+3x 3x+

5x x1+More

Practice

10

Explore- Using Tiles

What would you get if you combined

Agenda

5x + 3y + 2x + y? Use your tiles. x x x x x x xyy y y y+++x x x x x yy y+ x x+ y y+

11

Summary- No Tiles

Agenda

Commutative Property

Commutative Property

How can we combine without using tiles?

5x + 3y + 2x + y5x + 3y 2x+ y+Identify variables that are the sameIdentify variables that are the same

Now Combine!Now Combine!+

12

Agenda

Summary- Vocabulary

• Term: a single number, variable, or number and variables multiplied together.

Example

are terms in this expression.

• Like Terms: terms that have the same variable or power.

andand

13

Agenda

1. Copy the expression

3. Rewrite using the Commutative Property

4. Combine the variables that are the same

2. Identify the like terms

Summary- Process

5x + 3y 2x+ y+

Summary- Quick Check

Agenda

14

With your partner, write an equivalent expression for the following:

#1. 4a + 6b + 3a + 9b

#2. 15x – 4x + 12

#3. y + y + y#4. 5y + 7z

7a + 15b

11x + 12

3y

5y + 7z

Click for definition

Practice- Partners

16

Agenda

I. Model the following expression by drawing squares. Let = x = ya.

b.

+

+++

Practice- Partners

17

Agenda

II. Explain why the following statement is true.

2x and 4y are not like terms, therefore, you cannot combine them.

AnotherExplanation

Practice- Partners

19

Agenda

III. Write an equivalent expression for the following expressions.

1.

2.

3.

Practice- Partners

20

Agenda

IV. Explain Yvonne’s mistake in the following problem.

Yvonne just added all the numbers together. She can add numbers that are the like terms, 8x and 6x, but not 2 since it does not have an x.

Assessment- Exit Slip

21

Agenda

Jose and Amy were asked to combine 7x + 2y + 6y + 3x. Decide who is correct. Explain.

Jose 7x + 2y + 6y + 3x

Jose’s work

7x + 3x + 2y + 6y

10x + 8y18xy

7x + 2y + 6y + 3x = 18xy

Amy 7x + 2y + 6y + 3x Amy’s work

7x + 3x + 2y + 6y

10x + 8y

7x + 2y + 6y + 3x = 10x + 8y