This game combines higher-order thinking (in terms of developing a strategy) while reinforcing the properties of a triangle. It is a great context in which to encourage learners to re-think an approach when what they have tried doesn't work. You may like to read our Let's Get Flexible with Geometry article to find out more about developing learners' mathematical
flexibility through geometry.
It might be worth simplifying the game to start with so that you have just four pegs on your circular board. Introduce the class to the rules of the game, then challenge them to play against you. Allow time for several games to take place so that everyone really gets to grips with how to play.
Next, invite children to play in pairs. Their aim is to try to beat their partner. You may be able to set this up so that each pair has access to a computer so that they can use the interactivity. If this is not possible, using 'real' circular geoboards would be very helpful. Alternatively, you could print off appropriate sheets from this page. Here is a sheet of pegboards each with six pegs.
After a suitable length of time, bring everyone together to discuss progress. Has anyone found a good way of winning? Is it better to go first or second in this game? Encourage learners to explore the game more so that they try to come up with a strategy that always works.
In the plenary you could challenge a pair or group to beat you and then articulate how they knew they were going to win.
What triangle could you make first?
What could you do next?
Could you have done something different to start with?
Could you have done something different then?
Is it better to go first or second? Why?
Children could be challenged to play the game on a geoboard with more pegs. How does this affect the game?
Board Block Challenge offers more ideas for children to explore.
Playing the game on a print-out of the geoboard might help children as they will then have a record of the moves they made (see this page). They could then refer back to previous games more easily and refine their strategies.