Analogy for teaching recursion When teaching recursion, what is the best analogy people use to teach the idea of recursion. There are some nice artistic representations 



And the idea of repeatedly cutting a phone book or dictionary in half until you find a number/word (basically binary search). The only problem is students don't use phone books/paper dictionaries anymore and the artistic representation doesn't imply an end goal/state.
The Tower of Hanoi was one of the first ways that I encountered recursion.



"The objective of the puzzle is to move the entire stack to another rod, obeying the following simple rules:


Only one disk can be moved at a time.
Each move consists of taking the upper disk from one of the stacks and placing it on top of another stack i.e. a disk can only be moved if it is the uppermost disk on a stack.
No disk may be placed on top of a smaller disk." (from Wikipedia)


To solve the n disk tower problem:


Solve the n-1 disk tower problem 
Move the nth disk 
Solve the n-1 disk tower problem again.


Solving the 1 disk problem is trivial. 

I can imagine coding this as a nice on-screen or physical computing challenge.