Adding and Subtracting Matrices

Adding and Subtracting Matrices – Using Rainbows

This is the most important lesson in the Unit on Matrices! The easiest way to teach adding and subtracting matrices is by color coding.

Let’s Start Adding and Subtracting Matrices

I start with adding two 2×3 matrices. The reason I do not start with 2×2 matrices is because it is easier to show them that the matrices must be the same size to add or subtract them.
The other reason I use 2×3 matrices is because that means there will be 6 numbers inside each and there are 6 colors to the rainbow (I know that’s debatable but for the sake of the lesson go with it).
Each number from the first matrix gets matched with its Corresponding number in the second matrix. Then they are added or subtracted. I do this with a group activity.
Click Here to Download a Sample Set of Cards for the Activity: Adding and Subtracting Matrices – Using Rainbow Cards
Cards like the ones below are passed out to small groups and they find the solutions. The rest of the activity is available if you are a Algebra 2 Teacher Community Member: Click here to Join Now!
Here are two cards I use to introduce the lesson…
I always start with addition. Simply because it is easier.

Here is your free content for this lesson!

Adding and Subtracting Matrices Word Docs & PowerPoints

To gain access to our editable content Join the Algebra 2 Teacher Community!
Here you will find hundreds of lessons, a community of teachers for support, and materials that are always up to date with the latest standards.


4-2 Small Group Activity – Rainbow Cards (FREE)

4-2 Assignment Student Edition – Adding and Subtracting (FREE)

4-2 Assignment Teacher Edition – (Members Only)

4-2 Bell Work Student Edition (FREE)

4-2 Bell Work Teacher Edition – (Members Only)

4-2 Exit Quiz Student Edition (FREE)

4-2 Exit Quiz Teacher Edition – (Members Only)

4-2 Guided Notes Student Edition (FREE)

4-2 Guided Notes Teacher Edition – (Members Only)

4-2 Lesson Plan  (Members Only)

4-2 Online Activities (Members Only)

4-2 Slide Show  (FREE)

Want access to everything?

Simply click the image below to Get All of Our Lessons!

Get Access to 1,000s of Algebra 2 Lesson Plans
Click Here to Join Now!

Posted in Algebra 2 Worksheets, Blog, Matrices and tagged , , .