Comparing Data in a Bar Graph
Basics on the topic Comparing Data in a Bar Graph
How Can a Bar Graph Help You Compare Data?
Imagine this: you have collected data about the weather to try to predict what the weather will be like the next day so you can plan a day at the beach. You have recorded the total number of sunny, rainy, and windy days. Let’s see how you can compare this data with the help of a bar graph!
Bar Graphs – Definition
A bar graph is like a picture that is made up of bars of different lengths. Each bar represents a different category. The length of each bar can tell us how often something happens or show us the number of items we have in each group.
Comparing Data in a Bar Graph
Let’s see how our data compares! We have recorded three different types of weather: sunny, windy and rainy. This chart shows the individual amount of days with each weather type:
Type of weather  # of days 

sunny  8 
windy  5 
rainy  7 
All we have to do now is to set up our bar graph.
We set up a bar graph like this. We have our data categories on one side and a number scale alongside the other. We put a label by the numbers to tell us what we are counting. To record the data, count how many times a category appears and draw a bar that reaches to the number.
Now that the data is in the shape of bars, we can see the information easily. We see the sunny, windy and rainy days neatly organized and since the bars are next to one another, we can now compare the data visually. We can answer questions like which weather had the most or least amount of days. We can also use the bar graphs to help add or subtract the data.
Comparing Data in a Bar Graph – Further Practice
Why do you use bar graphs to represent data? Bar graphs help you to organize your data neatly and thereby enable you to visualize your data so that other people may find it easier to understand your data too. Following the video are more interactive exercises and worksheets to continue practicing looking at information on bar graphs and seeing why bar graphs are useful for comparing data.
Transcript Comparing Data in a Bar Graph
" The weather sure has been sunny lately." " Tomorrow, I think we should go to the beach." "Hmmm...I don't think the weather is always the same." "Maybe we can look at some weather data to guess what the weather might be like tomorrow!" We can help Nari and Gus by... "Comparing Data in Bar Graphs ". Data is information that we collect and put into groups based on things it has in common. When we put data on a graph, it makes it easier to see and understand. Here is a BAR GRAPH of weather data that Nari and Gus collected. It's called a bar graph because the data is in the shape of bars! On THIS side, you can see the three types of weather.... sunny, windy, and rainy. Along the bottom, you see numbers one through ten... and the label, 'Days'. The label tells us the numbers are counting how many days had each type of weather. In the center of the graph are the bars that show how many days each type of weather happened. Let's look at the chart to ask and answer questions about the data. We will COMPARE the data by looking at which type of weather had MORE days... and which type had LESS. First, let's see how many days had each type of weather. How many days had sunny weather? Point to the sun on the graph. Now look at the bar and move your finger to find where it stops. The bar stops on the number, eight. This means there were eight days of sunny weather. How many days had windy weather? Find the wind and look at where the bar stops. There were five windy days. How many days had rainy weather? There were seven rainy days. Which type of weather had the most amount of days? Looking at our graph, we look for which bar is the LONGEST. The sun bar is the longest, so there were MORE sunny days than windy and rainy days. Which type of weather had the least amount of days? Looking at our graph, we look for which bar is the SHORTEST. The wind bar is the shortest, so it had the LEAST amount of days. How many more days were sunny than rainy? First, look at the sun AND the rain bars. Then, find the number of days each bar shows the sun bar has eight... and the rain bar has seven. There was ONE more sunny day than rainy ones. Remember, today we learned about comparing data. Data is information that we collect and put into groups based on things it has in common. When we put data on a graph, it makes it easier to see and understand. A bar graph can help us answer questions about data: We can compare information like how many are in each group... and which groups have more... or less. "See, we have more sunny days, so tomorrow will be sunny!"
Comparing Data in a Bar Graph exercise

Can you highlight the bar graph?
HintsWhich bar is the tallest? This represents the weather that occurred the most.
Which bar is the shortest? This represents the weather that occurred the least.
SolutionSnowy was the type of weather that occurred the least. We can see from the bar graph that it only snowed on 3 days.
Cloudy was the type of weather that occurred the most. We can see from the bar graph that it was cloudy on 6 days.

What has the weather been like?
HintsLine up the top of each bar with the numbers on the side.
The taller the bar, the more days that type of weather occurred.
SolutionIf we line the top of each bar up with the numbers on the side we find that there were:
 4 sunny days
 5 rainy days
 3 snowy days
 6 cloudy days

Can you sort the data?
HintsWhich bar is the tallest? This is the most popular flavor and will go first.
If there is no bar that means that 0 of Nari and Gus's friends chose that flavor making it the least popular.
Solution Vanilla was the most popular flavor. 5 friends chose this flavor.
 Strawberry was the next most popular. 3 friends chose this flavor.
 Next was chocolate. 2 friends chose this flavor.
 The least popular flavor was mint choc chip. 0 friends chose this flavor.

Which colors are the friends' favorite?
HintsUse the data that you have to fill in the gaps in the table. Which number does each bar line up to?
When thinking about the most popular color, use all of the data you have.
 Which bar is the tallest?
 Which number is the biggest?
When thinking about the least popular color, use all of the data you have.
 Which bar is the shortest?
 Which number is the smallest?
SolutionHere is the completed table.
 The most popular color was green as 8 friends chose this color which is more than any other.
 The least popular color was yellow as 1 friend chose this color which is fewer than any other.

Which was the most popular fruit?
HintsMost popular means the option that was chosen the most times.
Which bar is the tallest? This is the most popular choice.
SolutionApple was the most popular choice.
7 friends chose apple as their favorite fruit compared to 4 for banana, 5 for orange and 2 for pear. This means that more friends chose apple making it the most popular choice.

Which charts represent the same data?
HintsFigure out what each chart is representing. How many people have each eye color?
Three images represent the same data set.
The charts that are representing the same data all have the same number in each category.
SolutionThis is the data set that was being represented in three images:
 the tally chart
 the bar graph
 the pictogram
 6 had brown eyes
 3 had blue eyes
 8 had grey eyes
 1 had green eyes