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Beads
Three beads are threaded on a circular wire and are coloured either red or blue.
Can you find all four different combinations?
You now repeat the following actions over and over again:
- between any two beads of the same colour put a red bead
- between any two beads of different colours put a blue bead
- then remove the original beads.
Why do this problem?
This activity 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.
Possible approach
It would be good to have some beads (or counters or...) for pupils to handle to get a feel for the task. This could lead quickly to some good classroom discussions.
Key questions
Why do you think that?
Tell me about you thoughts?
What do you mean by (such things as "goes on and on")?
Possible extension
Pupils encouraged to explore changing some of the numbers of beads. They could also change a rule slightly.
Possible support
Some practical apparatus to make a system of beads of their own.