I got invited back to help with the Railroad Merit Badge clinic this year.
Roy Severn has a nice O-scale setup he lets the boys run. First they have to learn about car types, train types, and how locomotive work. They also have to plan a trip by Amtrak using real time tables.
Here is an example of scales I set up, with my N-scale loco on the left and Roy's O-scale on the left. The center is the more popular HO. There are also smaller scales (Z) and larger (G)!
After work comes play. Roy teaches wiring and operations while I show them how to switch out the mill.
switching puzzle page.