Lesson 25 — Activity 1:

Identifying the Parts of a Graph

Getting Ready

Graphs are a part of everyday life. Sometimes it is confusing to just look at a bunch of numbers. Graphs can help you make decisions. By putting numbers into a graph, it gives you a visual picture of the information. Graphs are like vehicles, they come in many different sizes and shapes.

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In this activity, you will look at three of the most common types of graphs.

Three of the most common graphs are:

    Pie graph
    Bar graph
    Line graph

All graphs have a title, a legend, and data. You already know what a title and data are, but what is a legend?

A legend is a table on a map, chart, or the like, listing and explaining the symbols used. Look at the example below. The legend shows what the colours mean on the graph. Blue represents Asia, purple represents Africa, and yellow represents North America.

Courtesy of ADLC

Pie graphs (also called circle graphs) can be used to display information about such items as budgets, types of foods eaten, or the amount of time you spend on activities.

Click here for some more information about circle graphs.

Courtesy of ADLC

Courtesy of ADLC

Bar graphs can display information about such items as gas bills, power bills, or the number of calories you eat each day.

Click here for some more information about bar graphs.

Line graphs (also called broken line graphs) can be used to compare two items. Examples of this would be time vs. distance, height vs. weight, and gas used vs. distance travelled.

Click here for some more information about line graphs.

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Both bar and line graphs have specific terms that are involved with the graph.

Both use dependent and independent variables in order to make the graph.

Independent variables are numbers that don't depend on anything else.

Independent variables go on the bottom of the graph, or x-axis .

An example of an independent variable would be how tall you are.

Dependent variables are numbers that are affected by the independent variable .

Dependent variables go on the side of the graph, or the y-axis .

An example of a dependent variable would be your weight depending on how tall you are.

Look at the graph below. The independent variable is on the x-axis (the bottom) and shows boys height. The dependent variable is on the y-axis (the side) and shows boys weight.

 Courtesy of ADLC

Courtesy of ADLC 

An easy way to remember the variables is if you can say, "This depends on that."

Whatever goes in the "this" spot is your dependent variable , and whatever goes in the "that" spot is your independent variable .

Example: Weight depends on height . The dependent variable is weight and goes on the y-axis. The independent variable is height and goes on the x-axis. You will learn more about this later.


Try this!

Click here for a Flash activity where you will review the parts of a graph and look at some examples.