Coordinate grids usually have positive and negative numbers like the one
shown here.
As you can see the center point is at (0,0). Often the numbers are placed along the axis lines (the yellow lines in this picture). |
Coordinate grids can be divided into four quadrants as shown here. In the ++ quadrant all coordinate pairs are pairs of positive numbers such as (2,2), 5,3), and (9,1). In the +- quadrant all coordinate pairs are pairs in which a positive number is followed by a negative number such as (2,-3), (9,-1), and (5,-7). In the -- quadrant all coordinate pairs are pairs of negative numbers such as (-1,-1), (-6,-3), and (-3,-9). In the -+ quadrant all coordinate pairs are pairs in which a negative number is followed by a positive number such as (-9,4), (-3,3), and (-6,2). |