Grid Coordinates in Reverse: Read the Picture, Write the Codes

The picture is already finished on this 2nd grade grid-coordinates page, which is the whole of the reversal. A six by six grid is printed with letters A to F across the top and numbers 1 to 6 down the side, and most of its squares are filled in, twenty of them yellow and one orange. Beside the grid sits the same small worked example the other pages use, a three by three grid with one square shaded and B2 printed under it. The key below holds a yellow swatch followed by twenty empty white boxes and an orange swatch followed by one, and the child writes a code into every box.

Colouring a square from a code and naming a square you can see are not the same skill, and the second one is where coordinates actually get used: reading a reference off a map, saying which cell a value sits in. Producing the code means naming the column first and the row second, in that order, every time, and there is no picture emerging to signal a slip. What checks the work instead is the box count. Twenty yellow squares and twenty yellow boxes means a child who has missed one or written one twice will finish with a box left over, and finding which square was skipped is a second pass across the grid that is worth as much as the first.

Print the PDF free and let each square be crossed lightly in pencil as its code is written, since a coloured grid gives the eye nothing to hold on to otherwise. Working along a row at a time keeps the letters changing and the number fixed, which is the easier order. Grid coordinates on a 6x6 grid is this same grid the usual way round, with an empty picture and the codes supplied, and the 10x10 version is where the grid grows once both directions are secure.