An ordered pair is a set of two numbers that identifies a location on a map or in a coordinate system.
Sometimes a map will use a letter to represent one of the numbers in the ordered pair.
In the above map of Central America, some of the coordinates locate the countries of Mexico (B, 1), Belize (B, 3), Guatemala (C, 2), Honduras (C, 3), and Nicaragua (D, 4).
On the coordinate grid to the right, locate (3, 7) and (7, 3). Notice how the order of the numbers in the ordered pair makes a difference in the location of the point on the coordinate plane.
See also coordinate plane.