Coordinate graphing sounds complex but it is really just a visual way of showing the relationships between numbers. These relationships are shown on what is called a coordinate grid which as two perpendiculars lines, or axes, labeled like number lines. The horizontal axis is called the x-axis and the vertical is called the y-axis and the intersect is called the origin. The numbers on a coordinate grid are used to locate points. Each point is identified by an ordered pair of numbers. The number on the x-axis is called an x-coordinate and a number on the y-axis is called the y-coordinate. Ordered pairs are written in parentheses (x-coordinate, y-coordinate). The origin is located at (0,0).

The order in which you write x- and y-coordinates in an ordered pair is very important. The x-coordinate always comes first, followed by the y-coordinate. Now before you attempt to conquer coordinate graphs there are a few things that you need to know. You have to be able to differentiate between negative and positive numbers and be able to locate points on a number line. It is wise to start off with a basic number line and modeling where positive and negative numbers are on one axis before beginning with the coordinate plane. Stay in tune with all of the math terms or technical terms such as quadrants, axis, and coordinate plane, coordinate points, etc., then they won't seem so intimidating. Coordinate planes are used a lot throughout math and math related subjects (such as physics). They are most useful when you need to graph an equation. The graphing points on a coordinate plane are usually covered in the typical pre-algebra course.

So what makes coordinate graphing different from the rest? Pictographs, circle graphs, double bar graphs, comparison line graphs, these are all part of the algebraic graphing options that are available but it can be confusing and how is one to know which graph to use and when to use it. But wait-there are more choices, line graphs, pie charts, bar graphs, area graphs, and x-y plots now what? Line graphs are used to track changes over short and long periods of time. When smaller changes exist, line graphs are better to use than bar graphs. Line graphs can also be used to compare changes over the same period of time for more than one group. Pie charts are best to use when you are trying to compare parts of a whole. They do not show changes over time. Bar graphs are used to compare things between different groups or to track changes over time. However, when trying to measure change over time, bar graphs are best when the changes are larger. Area graphs are very similar to line graphs. They can be used to track changes over time for one or more groups. Area graphs are good to use when you are tracking the changes in two or more related groups that make up one whole category (for example public and private groups. X-Y plots are used to determine relationships between the two different things. The x-axis is used to measure one event (or variable) and the y-axis is used to measure the other. If both variables increase at the same time, they have a positive relationship. If one variable decreases while the other increases, they have a negative relationship. Sometimes the variables don't follow any pattern and have no relationship.

There are numerous graphs that can be used depending on what it is that you are trying to analyze or show. Decide which type of information that you are trying to display and then it should be much easier to know which graph to use and why.