Total Duration: 
31 to 60 Minutes 
Materials and Resources: 
Poster Paper or Poster with grid lines, sticky notes of different types, straight edge, markers, exit slips, student may use their own devices or teacher issued graphing calculators. 
Technology Resources Needed: 
Computer with Internet access, LCD Projector and Document camera to share student work (helpful but not necessary.) Smartview with calculator may be needed. 
Background/Preparation: 
Teachers
Students:

ENGAGE 1. As students enter the classroom, they should be given a group indicator that tells where to sit. Students will watch clips as a class: Scalar Multiplication, Scalar Matrix Multiplication, Multiply a Matrix by a Matrix from these websites 2. Students will listen and jot down important ideas. Inform the students that their mission will be to determine the process for multiplying Matrices. EXPLORE 3. Student groups will receive scalar and matrix multiplication problems with stepbystep work and solutions. Students should develop strategies for solving these matrices. Student groups will have matrix problems and solutions of square and different size matrices. They should record these findings on their own paper (this information is to be placed on poster paper and problems can be keyed into their graphing calculators if needed). 4. The students should determine if their strategies are reputable and mathematically sound. They should look for patterns and list them on chart paper. The groups must agree on findings and be able to justify. 5. If students are unable to understand Matrices and dimensions, provide necessary feedback to move them forward with their thinking. Refer to the previous clips again for review. EXPLAIN 6. The teacher should be sure that students are using Matrices and dimensions correctly. 7. Groups will discuss strategies discovered and begin justifying their ideas; Groups can use graphing calculators to input matrices for further justification. 8. Allow students time to prepare attractive posters to share with class to begin discussions about multiplying matrices, along with having the groups share their findings using the Smartview function of the calculator. Student Groups will receive exit slip the last 10 minutes of class. This should be turned in to the teacher as the groups exit the class. 
Attachments: **Some files will display in a new window. Others will prompt you to download. 
Assessment Strategies 
Use the exit slip provided in the last 10 minutes of class to assess student work individually and as a group. Students should justify all reasoning. Exit slips are to be shared with the class the next day at the beginning of class. The assessment process is ongoing. The teacher should visit each group while students are preparing posters for justified reasoning and ask questions to make sure students understand the process for multiplying matrices. Post the posters in the classroom and have students present conclusions. As students present posters, they should compare posters for other information not listed on their group's poster. 
Acceleration: 
Extensions can begin with a Computer Animation Activity: 
Intervention: 
For extra practice or for students who were absent have them visit: The Matrix Multiplication Song http://www.youtube.com/watch?v=BGbiHdKHG7o (if your school system does not allow youtube access, you may download the video using http://www.keepvid.com/). http://www.youtube.com/watch?v=YtMYfvypgM4 (if your school system does not allow youtube access, you may download the video using http://www.keepvid.com/). 
Each area below is a direct link to general teaching strategies/classroom accommodations for students with identified learning and/or behavior problems such as: reading or math performance below grade level; test or classroom assignments/quizzes at a failing level; failure to complete assignments independently; difficulty with shortterm memory, abstract concepts, staying on task, or following directions; poor peer interaction or temper tantrums, and other learning or behavior problems.
Presentation of Material  Environment 
Time Demands  Materials 
Attention  Using Groups and Peers 
Assisting the Reluctant Starter  Dealing with Inappropriate Behavior 