I introduce how to add matrices and work through three examples. I finish the lesson reviewing the Properties of Matrix Addition. This an excerpt of a full length lesson I will be posting in a few days.
Check out http://www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class. Find free review test, useful notes and more at http://www.mathplane.com If you'd like to make a donation to support my efforts look for the "Tip the Teacher" button on my channel's homepage / profrobbob