What can teenager teach kids beyond beginner level?

I am looking for advice for my 14 year old son. He is a pretty sharp kid and has a rating here of around 1350. He just taught a chess class in our homeschooling community to kids aged 7-11.  It was a basic class for beginners so now everybody knows how the pieces move, castling, basic opening strategy, controlling the middle, fork, pins, etc.

Well, the class went so well and the kids liked it so much, they have asked him to teach another class for this "semester" and they want to take it to a level a little beyond the basic beginner stuff. It is only 3 classes of an hour each so let's not throw too much at him. I am considering having him bring lots of chess puzzles to class and have them solve them but I am looking for your input. Should he be teaching something like all the first 5 moves of something like the Sicilian defense or is naming these openings and defenses even important? The class age will still be roughly the same. Any input you can offer is greatly appreciated. Thanks!

Don't teach specific openings, but general strategies that work for any opening: Development, center control and pawn structure.