1. When determining the position, the vertical rows are called columns and the horizontal rows are called rows. Determine which column is generally counted from left to right and which row is generally counted from front to back.

2.Number pair (x, y) The 1 th number indicates which column (x) and the second number indicates which row (y). When writing a number pair, write the number of columns first, then the number of rows.

3. Seen from the globe, it is the meridian connecting the North Pole and the South Pole, and the ring perpendicular to the meridian is the latitude. Longitude and latitude are arranged in a certain order, indicating "longitude" and "latitude" respectively, and both "longitude" and "latitude" are expressed in degrees (), minutes (') and seconds (").

4. Move a point to the left and right by several squares, except that the number on column (X) changes, decreases to the left and increases to the right, while the number on row (Y) remains unchanged. For example, the position of point (6, 3) is (8, 3) after being shifted to the right by 2 units, and column 6+2 = 8; The position of the point (6,3) is (4,3) after being shifted to the left by 2 units, and the column 6-2=4.