1. Bar Graphs

2. Look at the way a bar chart is constructed
Look at the way a bar chart is constructed. Can you name its different parts?
What goes here?
What is this called?
What is this?
What do we call this?

3. A bar chart always has a title.
Vertical axis (y). Always labelled and numbered.
The height of the bars show how many of something was scored/recorded.
Horizontal axis (x). Always labelled.

4. Can you read the answers?
What does this bar chart show?
How many children were surveyed?
Which is the favourite flavour?
Which is the least liked?
What intervals are used on the y axis?
What intervals could you use if twice as many children were surveyed?
Can you read the answers?
Favourite Crisps 8 7 6 5
Number of children 4 3 2 1
Salt and vinegar
Cheese and onion
Prawn cocktail
Ready salted
Bacon
Worcester sauce
Barbeque
Flavours

5. Types of Bar Graphs VERTICAL Graph 1.1
A bar graph is used to show relationships between groups. The two items being compared
do not need to affect each other. It is a fast way to show big differences. Items can be
represented in horizontal bars or in vertical columns. Look at the following graph which
shows the data using horizontal bars. Carefully read the title and the labels on each axis
to see what data is displayed by the graph.
Which food has the highest percent of sugar? Chocolate Bar
Which food has the lowest percent of sugar? Ketchup

6. Types of Bar Graphs H O R I Z O N T A L Graph 1.2
What is the most favored after school activity? Visit with Friends
What is the least favored after school activity? School Clubs
H O R I Z O N T A L

7. Types of Bar Graphs SINGLE BAR GRAPHS Graph 1.3
What two countries have the highest rate of unemployment? Finland and Sweden
Which country has the lowest rate of unemployment? Norway
If Finland’s population is 5.4 million people, how many are unemployed? 329,400
SINGLE BAR GRAPHS

8. Types of Bar Graphs DOUBLE BAR GRAPHS Graph 1.4
Which countries do men have a higher rate of unemployment? Iceland and Norway
DOUBLE BAR GRAPHS

9. The table shows the highway speed limits on interstate roads
The table shows the highway speed limits on interstate roads .within three states
Rural
Urban
State
70 mi/h
65mi/h
Florida
Texas
65 mi/h
55mi/h
Vermont

10. Step 1
Choose a scale and interval for the vertical axis.
Rural
Urban
State
70 mi/h
65mi/h
Florida
Texas
65 mi/h
55mi/h
Vermont

11. Step 2
Draw a pair of bars for each state’s data. Use different colors to show urban and rural.
Rural
Urban
State
70 mi/h
65mi/h
Florida
Texas
65 mi/h
55mi/h
Vermont

12. Step 3 and 4 Label the axes and give the graph a title.
Speed Limit on Interstate Roads
Label the axes and give the graph a title.
Make a key to show what each bar represents
Urban
Rural
Speed Limit (mi/h)

13. Types of Bar Graphs STACKED BAR GRAPHS Graph 1.5
How many cups of coffee were sold in January? 40
How many cups of coffee were sold downtown in February? Approx. 26
How many cups of coffee were sold at the mall in February? Approx. 42
What fraction of coffee that was sold in April was sold downtown? Approx. 2/3
What month were more cups of coffee sold downtown than at the mall? April
What percent of coffee was sold at the mall in May? Acceptable answers between 30-40%
What was the percent increase in cups of coffee sold from January to February? Acceptable answers between 65-70%
What is the ratio of coffee sold in March to the amount sold in May? Approx. 5:3
STACKED BAR GRAPHS

14. How can you collect the information needed to construct a bar chart?
By making a tally chart first!

15. Flavour Tally Salt and vinegar Sour Cream and Onion Ketchup Plain
Dill Pickle
BBQ
Insert any other flavours here

16. Create a Tally Chart with Chip Flavours
Go around the class and ask the favourite flavour
Construct a Bar Graph with the information
Be sure to label your axes correctly and give your graph a title
With support