Bats on Parade by Kathi Appelt

Mathematical Strand:

Algebra

Topic:

Students will visualize polynomials using algebra tiles

Grade Level:

6-8

Lesson Created by:

Marilyn Kilgore, Susan B. Anthony Middle School, Manhattan, KS

Lesson Description:

Materials

• The book Bats on Parade, algebra tiles
  

1. Launching the lesson (engage):

1. Read the story
   
2. Talk about the pattern in the story. Discuss how this pattern could be written algebraically?
   
3. We talked about polynomials earlier. Suppose we want to model polynomials using tiles. Today we are going to do hands on algebra using algebra tiles.
   

2. Developing the lesson

1. Ask the students what a variable is in math. Today we will concentrate on the variables "x" and "y" in various polynomials. Hand out packages of algebra tiles to each student.
   
2. Using the overhead algebra tiles show the students "x 2" Explain each side is x by x therefore equals x2. Show y 2 tile (y by y) and
   
3. xy tile (x by y).
   
4. Ask students to use their tiles and model 2x 2 and 3y 2 and 5xy and 3
   
5. x 2 + 2 xy etc.
   
6. Ask students what the additive inverse of x 2 is. Show the -x 2 tiles. Have the students show - y 2 and - xy and - 2 x 2 + - y 2 etc.
   
7. Have students pair up. One student will make up a polynomial using their tiles. Their partner will verbally tell the polynomial that is modeled. Each student will practice this 5 times each. To make sure they understand model a polynomial on the overhead and ask students to verbalize. (4 x 2 ) (-2xy) (X 2 - 3xy - y 2 ) (-3x 2 - xy + y 2)
   
8. Discuss like and unlike terms. Ask students to model like terms and then unlike terms. Ask student to model 0 with their tiles. Tell them this is the additive inverse or opposite.
   
9. Have all students model a polynomial such as (x 2 + 2 xy + 3 y 2) ask them to also model (2 x 2 + xy - y 2) ask them what the sum of these two polynomials would look like. Discuss the zero principle. Practice addition using the given problems.
   

3. Closure/Discussion/Elaboration

1. Discuss letting xy tiles representing (x by 1) instead of (x by y) and y2 tiles representing (1 by 1). Ask student to model 3 x 2 - 5x + 4 and 2x - 6. Ask them to find the sum of the polynomials.
   
2. Ask students to use the zero principle and show that the tiles x 2 and xy can be arranged in a rectangle whose dimensions are (x and x-y)