Poly Plug Battleships Years 2 - 6 Angela Breen & John Longden, Chigwell Primary School Note The NRICH web site has a neat, software-based complement to this activity which they call Poly Plug Rectangles. It offers several levels of challenge in the Teachers' Notes and video from classrooms.

with a photo from your classroom.
doug@blackdouglas.com.au

Aim

A game for two players in which you aim to sink your opponent's battleships.

Equipment

• 1 Poly Plug set per player
• Optional: A template marked A - E, 1 - 5 as axes, or one which can be read through the holes in a Poly Plug board and shows the co-ordinates of each hole. A Poly Plug Frame can be used in this way.

Rules

1. Remove all the plugs from the red board and store them in the bag.
2. Place the red board behind a screen (eg: an exercise book standing up on the table) and place 5 yellow plugs anywhere in the frame as battleships.
3. Take turns to guess the positions of your opponent's battleships by saying grid positions.
4. If there is a hit, turn the plug over so it is blue side up, and tell your opponent.
5. It is the caller's responsibility to find a way of using their remaining yellow/blue board and plugs to keep track of co-ordinates they have already called. Repeated co-ordinates waste a turn.
6. First to 'sink' all the opponent's battleships is the winner.

Extensions

• If you call a hit you get another turn.
• Use 1 aircraft carrier (4 plugs horizontal or vertical), 2 battleships (2 plugs horizontal, vertical or diagonal) and 2 submarines (1 plug).
• Internet Battleships.
Connect two players by email. They agree on a grid reference system and send the calls and results back and forth by email.

Calculating Changes ... is a division of ... Mathematics Centre