Human battleships

Before you begin

• Use the masking tape or chalk to make two identical grids on the floor next to each other. They should be five squares by five squares, and each square should be big enough for someone to stand in.
• Label the vertical lines at the bottom of each grid with numbers, increasing from left to right. You can use chalk to write on the floor, or pens and paper to make signs.
• Label the horizontal lines at the left-hand side of each grid with numbers, increasing from bottom to top.
• Make a screen between the grids. You could string a line of rope between them and hang a sheet across it, attach fabric between two flag poles, or use a free-standing clothes rail.

Chat about grid references

1. The person leading the game should ask everyone what they already know about four digit grid references. 
2. The person leading the game should explain how grid references work. Everyone should listen carefully, as they’ll need to use grid references to save their ships.

• • Maps usually have horizontal and vertical lines, which divide them into squares. The grids have these lines, too.
  • Just like on a map, the lines on the grid are numbered. These numbers let us name the squares.
  • The numbers which run horizontally along the bottom of the square go from left to right (west to east) so are called eastings.
  • The numbers which run vertically up the side of the square go from bottom to top (south to north) so are called northings.
  • To find the grid reference of a square, you give the numbers of the lines that meet in the bottom left corner.
  • The easting always comes before the northing in a grid reference. You can remember this if you know that you go ‘along the corridor, and then up the stairs’.
  • This is a four figure grid reference, because it’s made up of four digits (two for the easting and two for the northing). 

Play human battleships

1. Split into two teams.
2. One team should stand on each grid. Each player should stand inside one square. Each team should position themselves randomly across their grid.
3. One player from the first team should call out a grid reference.
4. If anyone from the opposite team is in that square, they should call out ‘you’ve sunk my battleship’. They’re now out of the game – they should go to the side and watch.
5. Repeat steps three and four with the other team calling out the grid reference.
6. Keep repeating steps three and four, with teams taking it in turns to call the grid references. They should try to remember which references have already been said, to avoid ‘wasting’ a turn on a square they know is empty.
7. The game ends when all a team’s battleships have been sunk and all of their players are out. The team with battleships left is the winner.