Frequency tables organise raw data
A frequency table groups each category with the number of times it appears.
| Fruit | Frequency |
|---|---|
| Apple | 6 |
| Banana | 4 |
| Orange | 5 |
Count each category carefully before drawing the chart.
Year 7
Construct bar charts, pictograms and frequency tables
Organise data clearly in tables and charts, choose sensible scales and keys, and read comparisons from the finished display.
Lesson overview
Statistics and data - representing data
A good chart makes data easy to read. Frequency tables organise raw results, bar charts compare categories clearly, and pictograms use a key to show amounts visually. To present data well, labels must be clear and the scale or key must match the numbers exactly.
Bar charts compare categories
Bar charts use equal-width bars and a consistent scale so categories can be compared fairly.
bar height
bar height
bar height
A broken or uneven scale can make the data look misleading.
Pictograms must use a key
If one symbol stands for 2 votes, 4 symbols stand for 8 votes.
Always check the key before reading or drawing a pictogram.
Worked example
A class chooses favourite pets: dog 8, cat 6, rabbit 4. Set up the data for a bar chart.
| Pet | Frequency |
|---|---|
| Dog | 8 |
| Cat | 6 |
| Rabbit | 4 |
- List each category once: dog, cat and rabbit.
- Write the matching frequency beside each category.
- Choose a simple scale, such as 1 square = 1 vote.
- Draw equal-width bars up to 8, 6 and 4.
Try it
Use the data carefully, then check that labels, scale and key all match.
Question 1
Which row belongs in the frequency table if 7 learners chose football?
| Sport | Frequency |
|---|---|
| Basketball | 5 |
| Tennis | 3 |
Question 2
What does 3 symbols show if the pictogram key is 1 symbol = 2 children?
Question 3
Which value should the bar reach for the category 'cat' if the frequency is 6?
Question 4
Why should bars in a bar chart have equal width?
| Feature | Why it matters |
|---|---|
| Equal widths | fair comparison |
| Labelled axis | clear values |
Question 5
Which display definitely needs a key?
counts shown directly
symbols need meaning
marks counted directly
Common mistakes
Watch for these when working through the lesson.
- Missing a category when counting the data.
- Using an unclear or inconsistent scale.
- Reading a pictogram without checking the key.
Related topics
These ideas fit closely with this lesson.
- Calculate mode, median, mean and range from small data sets.
- Plan, present and interpret a simple survey.
- Generate and explain sequences.