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This is the lesson on adding, subtracting, and scalar multiplication of matrices.  

Thursday, May 14, 2020                                          

Integrated Math 1: Riverdale High School

**Just FYI:  Matrices ALMOST ALWAYS show up on the ACT.  I have taught juniors for four years and every year students come to me after the ACT asking about matrices.  I have learned to go ahead and make sure students are taught this information ahead of time!!!!

**Please remember, this is a very cursory, introductory lesson to matrices.  There is a lot more to know, especially when it comes to the business world and their use in technology. Love you lots!!  – Mrs. Gospodarek

What is a Matrix? 

  • A Matrix is an array of numbers that represent some data. The plural of “matrix” is “matrices.”
  • The individual values in a matrix are called the
  • A matrix on its own has no value. It is just a representation of data.
    • The data could be representative of quantities manufactured in a factory, the speed of a rocket, etc.
    • A matrix is used in solving equations that represent business problems.
  • A matrix forms the basis of computer programming.

The size of a matrix is determined by the number of rows X the number of columns.

Each of the examples below would be said:

  • “two by two matrix”
  • “three by three matrix”
  • “five by two matrix.”



To add and subtract matrices, the matrices must be the same size. 

For additional resources regarding addition and subtraction of matrices, please visit:



Technologically, you can use your TI-84 calculators to work with matrices as well.  When you do your worksheet, try some using paper and pencil and others using your calculator.  It is important to be able to use technology to solve problems too.  There is no need to make things more difficult than they are. 


Check out this YouTube video to learn how to input your matrix into your calculator!



Scalar Multiplication of Matrices


To practice work regarding matrices, go to https://cdn.kutasoftware.com/Worksheets/Alg2/Basic%20Matrix%20Operations.pdf


There are several problems regarding addition, subtraction, and scalar multiplication. 

Integrated Math I (May4-8)

Hey Kiddos - Please access this document and DO YOUR BEST.  I want for your minds to remain active and engaged during this time.  No one can make you do your work but your motivation during this time will keep you going and lay the foundation for the future.  I love you guys and miss you! 
Mrs. Gospodarek

Integrated Math III (May4-8).Riverdale

Attached you will find lessons for each day, May 4 - 8, for Integrated Math 3, regarding statistics and data.  Please do your best.  Your learning is your responsibility during this time.  I can only provide you assistance and resources.  Remember you are important to me and loved.  Please let me know if there is ANYTHING you need.  


First of all, let me say how much I have been missing all of my kiddos.  You guys have been in my heart, mind, and prayers throughout the last month.  Even when things have difficult, please know that I love all of you and only want the best for you. You have been a blessing to me this past year.  
I am hoping to be back April 27 with you so we can continue our learning and finish the year strong. We do not currently know what the next several weeks hold regarding grades, finals, etc.   
In the meantime, I have posted the resources provided by the district and will post videos throughout the week regarding the skills you are to be practicing while we are all in quarantine.  
Please work on these as you are able and contact me via remind anytime you need help.  I may not be able to get back to you immediately, but I will get back to you!!!  Also, don't forget Mathia!  It is available and all modules have been unlocked. 
Please stay safe, wash your hands, stay home as much as possible, and keep your brains brilliant with lots of practice!!!  I love you guys!


If you are in need of a laptop to practice your academic (i.e. Mathematical) skills during this time, you may check one out from Riverdale Mondays from 9 - 11 am beginning April 6.  
Additionally, if you are in need of internet access, please see the link below to find information regarding free internet access available through either Comcast or Charter Communications for a period of sixty days.  
Obviously, not everyone owns their own TI-84 calculator either.  Once you have a laptop and internet access, please download the free program available for six months via Texas Instruments.