Why do this problem?
presents a very non-threatening challenge that could be used to get pupils thinking. It is one of those activities in which pupils will probably not have an instant idea of the solution and so encourage creative thinking.
It would be good to use a white board displaying the interactivity for pupils to come and try out. This could lead quickly to some good classroom discussions.
Why do you think that?
Tell me about you thoughts?
What do you mean by (such things as "goes on and on")?
Pupils encouraged to explore changing some of the numbers of beads. They could also change a rule slightly.
Some practical apparatus to make a system of beads of their own.