I am teaching a teen beginner tap class - ages 13-16. We have gotten through basics (simple combinations, basic turns, single timestep), but I'm at a loss for where to go next.

Half the class is picking up steps really fast and the other half is still having trouble figuring out how to coordinate simple movements. Each week the gap widens between the two levels. What can I do to keep class interesting for the faster learners, but not overwhelm the slower ones?

I kind of like combined levels. It can make the class a lot of fun. I am careful though not to make the slower learners feel bad about not "getting it". When I teach a class like this I show how to add sound to steps to increase the difficulty. For instance, the ones who have no trouble doing step ball change can do flap ball change. Progress steps from single, to double to triple. Add heel drops. I do rhythm exercises with stamps and claps, then start them in groups at different counts. the weaker dancers get to keep starting on count one, a mid-level group maybe on two or four, and the more advanced kids on oddball counts like three, five, or seven. Sometimes I have them do the same combo, one group at speed and the other half-time. It makes for some really interesting counter-rhythms. I have the class focus on how cool the sounds are when we do these types of things. I choose who is doing what, and they don't really even notice how I group them, so no one feels like they are holding the class up or waiting for someone else to "get it." One of my favorite things about teaching tap is how easy it is to mix levels.