Bar Graphs
Learn
Bar graphs use bars (rectangles) to show data. They make it easy to compare amounts because taller bars mean more!
What Is a Bar Graph?
A bar graph uses bars of different lengths to show and compare information. The length of each bar shows how much or how many.
Parts of a Bar Graph
- Title: Tells what the graph is about
- Bars: Rectangles that show amounts
- Labels: Tell what each bar represents
- Scale: Numbers that help you read the amounts
Reading a Bar Graph
To find out how many:
- Find the bar you want to read
- Look at where the bar ends
- Look across to the numbers (scale)
- Read the number - that is the amount!
Comparing with Bar Graphs
Bar graphs make comparing easy:
- The tallest bar shows the most
- The shortest bar shows the least
- Bars of the same height show equal amounts
Worked Examples
Example 1: Reading a Bar Graph
Problem: Look at this bar graph of Favorite Fruits:
Apples: |======| 6
Bananas: |====| 4
Oranges: |========| 8
Grapes: |==| 2
How many students chose oranges?
Step 1: Find the "Oranges" bar
Step 2: The bar reaches to 8
Answer: 8 students chose oranges
Example 2: Finding the Most
Problem: Using the same graph, which fruit was most popular?
Step 1: Look for the longest bar
Step 2: Oranges has the longest bar (8)
Answer: Oranges was the most popular fruit
Example 3: Finding the Difference
Problem: How many more students chose apples than grapes?
Step 1: Find apples: 6 students
Step 2: Find grapes: 2 students
Step 3: Subtract: 6 - 2 = 4
Answer: 4 more students chose apples than grapes
Example 4: Finding the Total
Problem: How many students voted in all?
Step 1: Add all the amounts: 6 + 4 + 8 + 2
Step 2: 6 + 4 = 10, then 10 + 8 = 18, then 18 + 2 = 20
Answer: 20 students voted in all
Example 5: Making a Bar Graph
Problem: Make a bar graph for: Red = 3, Blue = 5, Green = 2
Step 1: Write a title: "Favorite Colors"
Step 2: Draw bars for each color with the right length:
Red: |===| 3
Blue: |=====| 5
Green: |==| 2
Step 3: Add labels and a scale
Practice Problems
Use this bar graph to answer the questions:
Favorite Sports (Bar Graph)
Soccer: |========| 8
Basketball: |======| 6
Baseball: |====| 4
Tennis: |==| 2
Problem 1: How many students chose soccer?
Show Answer
8 students
Problem 2: Which sport was least popular?
Show Answer
Tennis (the shortest bar, only 2)
Problem 3: How many more chose soccer than baseball?
Show Answer
4 more (8 - 4 = 4)
Problem 4: How many students voted in total?
Show Answer
20 students (8 + 6 + 4 + 2 = 20)
Problem 5: Which sport got 6 votes?
Show Answer
Basketball
Problem 6: How many fewer chose tennis than basketball?
Show Answer
4 fewer (6 - 2 = 4)
Problem 7: Which two sports together equal 10 votes?
Show Answer
Basketball and Baseball (6 + 4 = 10)
Problem 8: Did more students choose soccer or basketball and tennis combined?
Show Answer
They are equal! Soccer = 8, Basketball + Tennis = 6 + 2 = 8
Problem 9: If 3 more students chose tennis, how many would that be?
Show Answer
5 students (2 + 3 = 5)
Problem 10: What would the graph look like if soccer and tennis had equal votes?
Show Answer
Their bars would be the same length. They would need to both be the same number.
Check Your Understanding
Question 1: What does a bar graph use to show data?
Show Answer
A bar graph uses bars (rectangles) of different lengths to show amounts.
Question 2: How can you tell which category has the most in a bar graph?
Show Answer
Look for the longest or tallest bar. That category has the most!
Question 3: What are the four main parts of a bar graph?
Show Answer
Title, bars, labels, and scale.
Question 4: Why are bar graphs helpful?
Show Answer
Bar graphs make it easy to compare amounts quickly. You can see at a glance which has more or less.
Next Steps
- Collect Data: Survey your classmates about their favorites and make a bar graph
- Practice: Find bar graphs in newspapers, books, or online
- Next Lesson: Learn about picture graphs!
- Challenge: Make a bar graph showing the weather each day for a week