Hi Laura and all! We do have a few sample matrix activities created by Dr. Katrina Palmer, a friend in the mathematical sciences department. I don't think we can post the document here at the chat page, but we will post it on the website (and Laura I'll email you). If others have trouble accessing or finding the page at the website let us know! Also, keep in mind that Dr. Palmer's examples range from algebra 1 appropriate up to integrated 2 appropriate, so you probably won't want to use them all.