Matrix Addition
This video covers the basics of matrices and how to add them together. I am trying my hand at Adobe Flash. Let me know how you like this new style by clicking “Comments >>” below.
Transcript:
Welcome to Your Tutor Online video lessons. Today we will look at matrices and matrix addition.
A matrix is a way to organize numbers. It has rows and columns. This gives us our dimensions. In this example, this matrix is a 2 by 3 matrix because it has two rows and three columns.
In order to add matrices they must have the same dimensions. Here, we have two matrices that have 2 rows and 2 columns each. All we have to do is add up the corresponding numbers in each matrix and put that answer in a new matrix in the same spot. So, we’ll start with the numbers in the first row, first column; add those together and put that answer in the first row, first column. We’ll repeat with the number in the first row, second column and so on for each number until you’ve got your answer.

Joel- I have been watching your videos so I can help my son who is in Algebra 2 and you lost me on the Matrix lesson. You put “In order to add matrices they must have the same dimensions. Here, we have two matrices that have 2 rows and 2 columns each. All we have to do is add up the corresponding numbers in each matrix and put that answer in a new matrix in the same spot.” How do I know what the same dimensions are? You didn’t go into that and so I was lost for the first time. This is the first lesson I watched where you were doing everything computerized and not showing by hand so I am not sure where your numbers came from. Just my thought.
Karen
9 Jan 11 at 7:21 am
@Karen
Thank you for the honest and very helpful critique! I’ll add this one to the list of lessons to improve.
Joel
9 Jan 11 at 5:13 pm