Lesson Objectives

When the students have completed this lesson they should
be able to:

NYS Standards:

8A5 Use physical models to perform operations with
polynomials .

8A7 Add and subtract polynomials with integer coefficients.

NCTM Standards:

1. create and use representations to organize, record, and
communicate mathematical

ideas.

2. select, apply, and translate among mathematical
representations to solve problems .

3. recognize and use connections among mathematical ideas.

4. understand how mathematical ideas interconnect and
build on one another to produce

a coherent whole.

5. communicate their mathematical thinking coherently and
clearly to peers, teachers,

and others.

6. model and solve contextualized problems using various
representations, such as graph ,

tables, and equations .

Text Book Resources

Algebra 1, Glencoe Mathematics (2005) McGraw-Hill
Companies

Chapter 8 Pgs. 437-438

Adding and Subtracting Polynomials Using Algebra Tiles

**Objective:** The student will be able to use algebra
tiles to add and subtract polynomials

**Materials:** Class set of algebra tiles, Overhead
Algebra Tiles, and an overhead

**Procedure:**

Warm Ups (10 minutes):

The beginning of the lesson will consist of the teacher reviewing students prior

knowledge of adding and subtracting polynomials by doing two examples on the
board.

Students will work along in their notebooks as the teacher works on the board.

First, students distribute to drop the parenthesis.
Second, they combine like terms . All

work must be shown in their notebooks. The teacher will then go on to introduce
the

Algebra Tiles.

Activity 1 (20 minutes):

Using the overhead, the teacher will display one of each tile to represents the
size, color,

and value. Students can also refer to the poster hanging in front of the class
throughout

the lesson for the value of each algebra tile. At this point, the teacher will
pass out

student sets of algebra tiles. Allow students a few minutes to explore the tiles
on their

own. Note that all the red tiles are negative and the blue , green and yellow are
positive.

The students know about zero pairs from adding and
subtracting polynomials. Briefly

describe a zero pair on the overhead using the algebra tiles. Explain that
adding a zero

pair to the polynomial does not change its value because the zero pairs are
equal to zero.

Using the first example of adding polynomials from the
board, display the algebra tiles

to match the polynomial. As the teacher is working at the overhead, the students
are

recreating the polynomial with their set of tiles. The teacher will explain that
when

adding and subtracting polynomials, it is easier to use the tiles to model the
polynomials

if they arrange the tiles in the same order that the monomials are arranged
within each

polynomial. Therefore, arrange the tiles in descending order form left to right
on their

desks. All the x^2 tiles go on the left, the x tiles go in the middle, and the 1
tiles go on

the right. Show students how the result of the model can show a way to add the

polynomials. Remember to combine like terms and take away zero pairs.

Give students a chance to explore the other example
problem with the algebra tiles before

having them work independently on their class work. Demonstrate Example 2 from
the

board on the overhead with the tiles. Remember to distribute the negative
throughout the

second monomial .

Activity 2 (25 minutes):

Have students complete the “Exploring adding and subtracting polynomials”
worksheet

#1-6, with their algebra tiles. Students are to complete each problem in their
notebook as

well as using the tiles to solve the problems. After students have completed the
first

problem on their own, the teacher will work out the problem on the overhead with
the

algebra tiles and show students how to arrive to the correct answer. The teacher
will then

allow the students to continue working on the worksheet exploring how to use the
tiles.

After students have had time to explore, the teacher can then ask students to
volunteer

their solution by coming up to the overhead and demonstrating how they used the
tiles to

get their answers.

Closing (5minutes):

The teacher will then wrap up the lesson by asking a student to summarize the
lesson on

algebra tiles for the rest of the class. The teacher will add any other comments
needed

and let the class know how the lesson went. Assign Page 438, #1-7 for homework.
Let

students know they can use their algebra tiles to help them solve the homework
problems.

All problems must be done in their math notebook.

## Exploring Adding and Subtracting Polynomials

**Directions: **Solve each polynomial when adding or
subtracting and draw the

representation of algebra tiles for each problem as well.

## Exploring Adding and Subtracting Polynomials (Ans.Key)

**Directions:** Solve each polynomial when adding or
subtracting and draw the

representation of algebra tiles for each problem as well.