Grade by Grade
D. Data · Data and Probability

Multiple-Bar Graphs

D1.3 D1.6About 45 minutes
Learning goals
  • I can read a multiple-bar graph using its legend and scale.
  • I can compare two or more sets of data in a multiple-bar graph.
  • I can make a multiple-bar graph with a title, labels, a legend, a good scale and a source.

Words to know

multiple-bar graph
A bar graph that shows two or more sets of data side by side, so you can compare them. With two sets it is often called a double-bar graph.
legend
The part of a graph that shows which bar stands for which set of data. It is also called a key.
scale
The numbers along the side of a bar graph. A good scale starts at 0 and goes up by the same amount each time.
interval
The amount the scale goes up by each time, like 2, 5 or 10.
source
Where the data came from.

Remember from Grade 3

You made bar graphs with a scale that counted by 2s, 5s or 10s, and you included a title, labels and a source. A multiple-bar graph uses all of these, plus one new part: a legend.

Comparing two classes at a glance

In the last lesson, the Grade 4 and Grade 1 classes chose their favourite winter activities. We could make two bar graphs. But it is much easier to compare if we put the bars for both classes side by side on one graph. That is a multiple-bar graph.

Favourite Winter ActivityGrade 4Grade 102468101214SkatingSleddingSkiingSnowmenActivityNumber of studentsSource: class surveys, January 2026
In each pair, the left bar (green) is Grade 4 and the right bar (blue) is Grade 1. The scale counts by 2s.

How to read it

  1. Read the title: what is the graph about?
  2. Read the legend: which bar is which group? Here, the first bar in each pair is Grade 4 and the second is Grade 1.
  3. Read the scale: it counts by 2s.
  4. Look at the top of a bar and follow it across to the scale. If the top is halfway between two lines, the value is halfway between them.
Worked example

Example 1: Read and compare

Use the winter activity graph. How many students in each class chose snowmen? Which class liked snowmen more, and by how many?

  1. Find the Snowmen pair of bars.
  2. The Grade 4 bar reaches the line for 6.
  3. The Grade 1 bar is halfway between 10 and 12, so it shows 11.
  4. 11 − 6 = 5.

6 Grade 4 students and 11 Grade 1 students chose snowmen. Grade 1 liked snowmen more, by 5 students.

More than two sets

A multiple-bar graph can show three or more sets of data. This graph compares how many books three reading groups read in three months. Each month has three bars, one per group. The scale counts by 5s.

Books Read by Reading GroupsOwlsFoxesBeavers051015202530OctoberNovemberDecemberMonthNumber of booksSource: reading logs
In each month, the bars are in the legend's order: Owls (green), Foxes (yellow), Beavers (blue). The scale counts by 5s.
Worked example

Example 2: Look for a pattern

Use the reading groups graph. Which group read more books each month than it did the month before? How many books did that group read altogether?

  1. Owls: October 15, November 20, December 25. It goes up each month.
  2. Foxes: 20, 15, 30. It went down in November.
  3. Beavers: 10, 25, 20. It went down in December.
  4. Owls total: 15 + 20 + 25 = 60 books.

The Owls read more books each month than the month before: 60 books altogether. (They never read the most in a month, but their number went up every time.)

Worked example

Example 3: Make a multiple-bar graph

Make a multiple-bar graph from this survey: Favourite fall fruit. Grade 4 students: Apples 9, Pears 3, Grapes 7, Plums 2. Adults: Apples 7, Pears 5, Grapes 4, Plums 6.

  1. Write a title: Favourite Fall Fruit.
  2. Draw the axes. Label the bottom Fruit and the side Number of people.
  3. Choose a scale. The largest value is 9, so count by 2s from 0 to 10. That gives 5 even steps that fit on the paper.
  4. Write the fruits along the bottom, leaving space for two bars in each spot.
  5. Make a legend: one colour (or pattern) for Grade 4 students and another for Adults.
  6. Draw each pair of bars touching each other, always in the same order. Bars with odd values, like 9, stop halfway between two lines.
  7. Write the source under the graph.

See the finished graph below.

Favourite Fall FruitGrade 4 studentsAdults0246810ApplesPearsGrapesPlumsFruitNumber of peopleSource: our survey, October 2026
Finished graph. In each pair, the left bar (green) is Grade 4 students and the right bar (blue) is adults.

Every good multiple-bar graph has

  • a title
  • labels on both axes
  • a scale that starts at 0 and goes up by equal steps
  • a legend that shows which bar is which set
  • bars of the same width, in the same order in every group
  • a source
Just for fun

Why did the two bars in the graph always stand side by side?

They were bar-st friends!

Hands-on activity

Graph your kids versus grown-ups survey

You need: your survey data from the last lesson (or a new survey of kids and grown-ups), grid paper or lined paper, a ruler, and two different pencil crayons.

  1. Choose your scale. Look at your biggest number. Count by 1s if it is small, or by 2s if it is bigger than 10.
  2. Draw the axes with a ruler and label them.
  3. Make a legend: one pencil crayon for kids, one for grown-ups.
  4. Draw a pair of bars for each answer, side by side.
  5. Add a title and a source (like "Source: my survey, November 2026").
  6. Write two sentences that compare the groups.

Math talk: show your graph to a family member. Can they read it without your help? If not, what part could be clearer?

Your turn

1

Winter activity graph: how many Grade 4 students chose sledding?

2

How many Grade 1 students chose skating?

3

Which activity did more Grade 1 students than Grade 4 students choose?

4

How many more Grade 4 students than Grade 1 students chose skating?

5

Which activity was chosen by the most students altogether?

6

What does the legend tell you?

7

Reading groups graph: in which month did the Beavers read the most?

More practice: warm-up

1

Reading groups graph: how many books did the Owls read in October?

2

How many books did the Foxes read in December?

3

What is the interval of the scale on the reading groups graph?

4

How many groups does the reading groups graph compare?

5

Which group read 20 books in October?

More practice: on your own

1

In November, how many more books did the Beavers read than the Foxes?

2

How many books did the Foxes read altogether?

3

Fruit graph: how many more adults than students chose plums?

4

You want to compare the favourite pets of kids and adults. Would you use a bar graph or a multiple-bar graph? Why?

5

Elena's scale counts by 2s. She needs to draw a bar for 7. Where should the bar stop?

Challenge

1

How many books did all three reading groups read in December?

2

Jon says, "The Foxes read the most books over the three months." Is he right? Show your work.

3

Why would counting by 1s be a poor scale for the reading groups graph?

Check your understanding

Quiz

1.

What does the legend on a multiple-bar graph show?

2.

When is a multiple-bar graph the best choice?

3.

A scale counts by 2s. A bar stops halfway between 8 and 10. What value does it show?

4.

Winter activity graph: how many students chose skiing altogether?

5.

Which scale is best for data with a largest value of 45?

6.

Reading groups graph: which group read the fewest books in October?

For parents and teachers

What this lesson teaches: reading and making multiple-bar graphs, which show two or more sets of data side by side, with a title, axis labels, an equal-step scale starting at 0, a legend and a source (D1.3), and using them to compare groups (D1.6).

How to help at home:

  • Look for double-bar graphs in flyers, news stories or sports pages and read them together: "What does the legend say? What is the scale counting by?"
  • Help your child choose a scale for their own graph: look at the largest value and pick an interval that gives about 5 to 10 steps.

Common difficulties:

  • Ignoring the legend and mixing up which bar is which group.
  • Counting grid lines instead of reading the scale.
  • Bars for odd numbers on a scale of 2s: they stop halfway between lines.
  • Drawing the pairs in a different order in different groups.