I have kids with both models of calculators, and I find that just giving them print instructions to work through at their own pace is the most efficient way for them to learn button-press procedures. It's either that or a live demonstration, and then you have to wait for everyone to keep up with you, and they don't have something they can look at later. On top of that, half the kids are not fluent English speakers, so I try not to make verbal instructions the only mode of communication, ever. The point of this is not for them to learn any math. We're doing other stuff for that. (So lay off about the inauthenticity of this task, please.) It's purely to learn the button presses. I spent way too much time making these, so please, take them so you don't have to duplicate my efforts. Also, disclaimer, these assume your handhelds have the latest operating systems. Which are way better than previous versions, so update yo' shit, people.
Nspire Regression Instructions (docx)
Nspire Regression Instructions (pdf)
84 Regression Instructions (docx)
84 Regression Instructions (pdf)