Graph It!

Lesson Plan - Get It!

Audio:

A fun topic in math is graphing.

Graphing is when you represent information in the form of an illustration or picture. Before you learn how to make a graph, you need to know what a graph looks like and how to read a graph.

In this lesson, you are going to learn about pictographs and bar graphs:

• A pictograph is a graph that uses pictures to represent the data.
• A bar graph is a graph that uses bars to represent the data.

Let's watch Pictographs and Bar Graphs, from Tony Zobeck, to learn more about these fun ways to represent information and data:

In the video, you got to see different examples of bar graphs and pictographs. Now, let's take a closer look.

Below are pictures of each type of graph. Following each picture is an explanation of how to read each graph.

Pictograph

The picture above is an example of a pictograph. At the top of the graph is the title:

The title tells you what the graph is representing. For example, this graph tells you all of the different types of apples that are available at the local grocery store.

Along the left side of the graph are the types of apples:

The categories represent the information that the graph is representing. For example, the categories in this graph represent all the different varieties of apples in the store. Those varieties include Red Delicious, Golden Delicious, Red Rome, McIntosh, and Jonathan.

Now let's take a look at the key:

The key tells you the quantity each picture represents. In this graph, each whole apple represents 10 apples.

Take a look at the first type of apple in the graph, which is Red Delicious. There are 3 whole apples in that row. That means there are 30 Red Delicious apples in the store.

Remember, each whole apple represents 10 apples. If you have 3 apples next to the variety or type of apple, you just need to count by 10 (10, 20, 30).

Take some time to figure out how many Golden Delicious, Red Rome, McIntosh, and Jonathan apples are in the store. Be careful of that tricky half apple!

Besides being able to quickly see how many of each variety of apples are in the store, you can also see other information quickly as well.

• For example, which type of apple is most popular?
• Most likely the one with the least amount left in the store, right?

So, that would be McIntosh.

• Which variety do you think is the least popular? Why?

As you can see, a pictograph uses pictures to help represent and communicate information so you can read it quickly.

• Could you make a pictograph of the same information in a different way?

Sure you can. You could change the picture used to represent the number of each type of apple available in the store. Instead of using an apple, maybe you would like to use a picture of a tree, a pie, or even a smiley face!

If you did change the picture, you would have to change the picture in the key.

Use a piece of paper, a ruler, and markers or colored pencils and see if you can draw your own pictograph of the information from the example above.

Bar graph

The picture above is an example of a bar graph. Just like a pictograph, a bar graph represents information in a way that is easy for you to see and understand.

The bar graph above has a title:

Just like the pictograph, the title of the bar graph tells you what information the graph is representing. A group of students was asked to share their favorite color.

What is different between the pictograph and the bar graph is the way the information is represented in the graph. Bar graphs do not use pictures like pictographs do.

Also, bar graphs show two categories. The bar graph above shows the category of colors and the category of number of students. Take a closer look at each category.

On the left side of the graph, you can see the label Number of Students along with the numbers 0, 5, 10, 15, 20, and 25:

This part of the graph will help you see how many students like each of the colors represented in this graph.

Across the bottom of the graph, you will see the color words red, blue, green, purple, and orange and the label Favorite Color: 

The labels Number of Students and Favorite Color are there to help you understand the graph and the information represented in the graph.

• What do you think the bar graph was telling you if it did not have the labels?

You could say it was telling you something about the colors, but you probably would not be able to say what it was telling you about the colors. You might think it was telling you how many of each color block was in a container. You also could think it was telling you how many of each color shirt your favorite store sells.

So you see, the labels in a bar graph are very important!

Now it is time to read the bar graph above. You now know that it is telling you how many students like each of the colors listed in the graph.

• How many students like the color red?

One trick that can help you read a bar graph easily if it is on a piece of paper in front of you, is to take a ruler and put it across the top of the column you are reading.

Look at the pictures below to see how to do this:

In this first picture, you can see that I lined my ruler up with the top of the red column.

In the second picture (below) I slid my ruler so that it touches the number line so that I can see how many students like the color red:

You can now see that between 20 and 25 students like the color red.

It is important for you to know that when you make your own bar graph, you can use whatever numbers you want. The only thing that will help you decide what numbers to use is the amount of information you are representing in the graph.

• For example, what if you have 100 pennies and you want to know how many pennies fit into a large container, a medium container, and a small container?

You probably would not write your numbers up the side of the graph in ones (0, 1, 2, 3, …). You would probably want to write them in tens (0, 10, 20, …).

Below is a picture where I used a ruler to help me figure out how many students like the color green. Take a look at the picture and see if you can figure out how many students like the color green:

Another thing you need to know about bar graphs is that you can draw one like the example you have been working with, or you can draw one like the picture below:

This bar graph has the numbers along the bottom and the category words going up the side. Take some time to read this graph.

One last thing to know about bar graphs is that they can have keys like the pictograph. Not every bar graph has a key, but some do.

Here is an example of a bar graph that has a key:

The bigger picture is the whole bar graph, and the smaller picture is the key that is located in the upper right corner of the graph. The key tells you that the yellow columns represent girls and the red columns represent boys.

• What is the bar graph about?

Read the information in the bar graph out loud.

Now that you know how to read a graph, it is time to learn how to make one!

For the activity below, you will read the information and make a pictograph and a bar graph representing the information.

You will need two pieces of blank white paper, a ruler, and markers or colored pencils.

Information

Five friends each have their own container of marbles. They want to put together a graph to show who has the most marbles. The amount each friend has is listed below:

• Anthony has 25 marbles
• Betty has 10 marbles
• Carl has 30 marbles
• Debbie has 5 marbles
• Ed has 15 marbles

Make a pictograph representing how many marbles each friend has.

1. Step one is to take a blank piece of white paper and put it in front of you on the desk or table.

2. Step two is to take your ruler and a black marker or colored pencil and draw your graph. See the picture below:

3. Step three is to give your pictograph a title. Think about what you are going to show in the pictograph (how many marbles each friend owns), and make your own original title for your graph.

4. Step four is to write each friend's name in the graph. You can write them in any order you want.

5. Step five is to make the key. You now need to decide what picture you are going to use to represent marbles and how many marbles one picture will represent.

For example, maybe you choose to use a circle as your picture, and you choose to say that each circle represents 5 marbles. Put your key at the bottom of your graph.

5. The last step of making your pictograph is to fill in the marble amount next to each person’s name. The picture below shows an example of how to fill out Anthony’s amount of marbles.

In this example, each circle represents 5 marbles. Anthony has 25 marbles, so he will have 5 circles next to his name.

6. Fill out the entire pictograph. Hang it in your workspace to help you remember what a pictograph is.

Now, let's make a bar graph using the same information from the beginning of this activity.

1. Step one is to put the other blank piece of white paper on the desk or table in front of you.

2. Step two is to use the ruler and markers or colored pencils to draw your graph:

3. Step three is to give your graph a title and write it at the top of the graph. You can use the same title that you used in the pictograph or make another one.

4. Step four is to place the numbers into your graph. You can choose whether you want the number to go up the side or across the bottom:

5. Step five is to place each friend's name on the graph. If you choose to put the numbers up the side, then the names go across the bottom. If you choose to put the numbers across the bottom, then the friends' names go up the side.

6. The last step is to make the columns that represent the number of marbles each person has.

7. Finish putting the other friends' information into your graph. You may want to hang your graph on the wall in your workspace to help you remember what a bar graph looks like.

Now that you have learned what a graph looks like, how to read a graph, and how to construct a graph, you are going to work on some activities to make sure you understand all of this new information!

Continue on to the Got It! section for the activities!