Divide the grid reference for the square in half. Coordinates for grid squares consist of four digits, so divide it into two sets of two digits. For example, to locate grid square 1268, split it into 12 and 68. These two numbers describe the East-West and the North-South location of the grid square.
Look along the bottom of the map for a vertical grid line marked with the first number. This number, called "Right" or an "Easting," identifies the vertical row of squares to its right.
Look along the left-hand edge of the map for a horizontal grid line marked with the second number. This number, called "Up" or a "Northing," identifies the horizontal row of squares above it.
Trace the vertical line up the map until you intersect the horizontal line. The square above and to the right of the intersection is the grid square you want to locate.
