Here is a treasure-island map. It has letters running along the top and numbers running down the side. Somewhere on it is a palm tree.

A grid reference is a short code, like B3, that names one square. The letters name each column going across, and the numbers name each row going down the side. To name a square we read the column letter first, then the row number.

Look at where the castle sits. On my cue, call out its grid reference all together, then we will check it on the board.

Now a second grid. Watch which way the letter takes you and which way the number takes you, then call out this square together on my cue.

Here is a grid with a square right in a corner. Call out the letter and the number it needs, then we will confirm it.

Today we work through these squares together: first we find A3, then C1, then D5, and last the corner square F1.

Today we solve these in order, each one a step harder: first find B3, then find D1, then name the square the ship sits in, and last name the bottom-right corner square F6.