Bar Graphs
Compare categories using bars.
Key idea
Compare categories using bars.
In depth
A bar graph compares categories with bars whose lengths show counts. Bars should have equal widths and gaps between them, and the vertical axis should start at zero so lengths are honest.
Worked example
Plot favourite fruits: apples 12, bananas 8, grapes 5, with a bar for each.
Real-world uses
- Comparing favourite sports across a class or sales by month in a business report
Common mistake
Truncating the axis, which exaggerates differences.
How to learn this
- Read the key idea and say it in your own words.
- Work through the worked example, then try a similar problem.
- Use the interactive lesson’s visual and mini-quiz to check the pattern.
Frequently asked questions
What is Bar Graphs?
Compare categories using bars. It is a topic at the beginner level in Probability & Statistics.
Where is Bar Graphs used in real life?
Real-world examples: Comparing favourite sports across a class or sales by month in a business report.
What should I learn before Bar Graphs?
Make sure you are comfortable with Tally Charts and Pictographs, the previous topic in Probability & Statistics.
What is a common mistake with Bar Graphs?
Truncating the axis, which exaggerates differences.
How can I practise Bar Graphs?
Open the interactive lesson, play with the visual, then answer the three-question mini-quiz. Getting two right marks the topic complete.
What comes after Bar Graphs?
Move on to Pie Charts next.
Related beginner topics in Probability & Statistics
- Types of Data – Categorical vs numerical, discrete vs continuous.
- Frequency Tables – Count how often each value occurs.
- Tally Charts and Pictographs – Simple visual summaries of counts.
- Pie Charts – Show parts of a whole as sectors.
- Line Graphs – Show change over time.
- Mode – The most frequent value.