What is the rule for reading grid coordinates?

The rule for reading grid coordinates involves interpreting the values on a grid in a specific manner to accurately determine locations. The correct method is to read the coordinates starting with the easting (the horizontal value) and then moving to the northing (the vertical value). This means that one typically reads from left to right to determine the easting value before moving downward to find the northing.

In the case of grid coordinates, while it is common to interpret them as first taking the horizontal reading and then the vertical, the essence lies in the standard practice of understanding how grid systems are structured. The choice of reading right (reflecting the easting) and then moving down to find the northing upholds this established convention in mapping and navigation.

The other methods, such as reading left and down, reading right and up, or reading upward and left, do not align with this convention and would generally lead to interpreting coordinates inaccurately, which could result in locating positions incorrectly on a map. Therefore, the right choice follows the accepted norm of systematically identifying the easting first and then the northing.