### Sumo

Reasoning based on this Japanese activity.

### Line of Four

A game somewhat similar to 'noughts and crosses' on a much larger space.

### Two Stones

This game is known as Pong hau k'i in China and Ou-moul-ko-no in Korea. Find a friend to play or try the interactive version online.

# Board Block

## Board Block

You can play this game for two players on the interactive pegboard, or on a real circular pegboard if you have one.  Or you could print off sheets of circles from this page.

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How to play:

Firstly, choose the number of pegs on your board.
Take it in turns to add a band to the board.
Bands must fit round three pegs, in other words, each must make a triangle.
A band can share a peg with other bands, but the triangles must not overlap (except along the edges and pegs).

A player loses when they cannot make a triangle on their turn.

What are the winning strategies?
Once you've mastered this game, why not play to lose?
You might like to extend the game - have a look at this for a more challenging version.

Perhaps you can invent some of your own games using the pegboard? You'll need to think about the rules of the game and what players need to do to win.

#### Why play this game?

This game combines higher-order thinking (in terms of developing a strategy) with reinforcing the properties of a triangle.

#### Possible approach

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 fool-proof strategy.

In the plenary you could challenge a pair or group to beat you and then articulate how they knew they were going to win.

#### Key questions

What triangle could you make first?
What could you do next?