[zwieback]

I think it's very helpful to work back to the math, if the students are capable of understanding it. You can start with the familiar white-piano-keys scale and build forward, exactly like the article shows. Eventually, though, it's important to understand the math and how the different tempers were derived.

Instead of math maybe show pictures of sine waves and how they relate. My kids learned that in elementary school and it seemed to make sense to them. You can even demonstrate it pretty easily with long strings and a cheap strobe or the 60Hz lighting in the room.