Read, interpret and create bar charts, line graphs, pictograms, pie charts and frequency tables!
A frequency table records how often each value or category occurs. Tally marks (| | | | ||||) group data in fives for easy counting.
Relative frequency: frequency ÷ total × 100 gives the percentage.
| Category | Tally | Frequency |
|---|---|---|
| Football | |||| |||| |||| | 15 |
| Tennis | |||| |||| || | 12 |
| Swimming | |||| |||| | 10 |
A bar chart uses rectangular bars to show the frequency of each category. The height (or length) of each bar equals its frequency. The axes must be labelled.
Reading bar charts: Find the value by reading the height of each bar against the y-axis scale.
A line graph shows how data changes over time. Points are plotted and joined with straight lines. Good for showing trends (going up, going down, staying the same).
Reading line graphs: Find the data point on the x-axis (time), then read across to the y-axis (value).
A pictogram uses symbols or pictures to represent data. A key tells you how many each symbol represents.
If a symbol is cut in half, it represents half the key value. Always check the key!
Example: Key = 🍦 = 4 students. Three symbols = 3 × 4 = 12 students.
A pie chart (circle chart) shows data as sectors of a circle. The whole circle = 360°, representing 100% of the data.
To find a percentage: angle ÷ 360 × 100 = %
Example: Sector = 90°, Total = 360 students → frequency = (90 ÷ 360) × 360 = 90 students
A class voted for their favourite sport. Total = 50 students. Football = 15, Tennis = 12, Swimming = 10. What percentage chose swimming?
Books read per month: Jan=5, Feb=8, Mar=12, Apr=7, May=10, Jun=6. Find the mean.
A pie chart shows 360 students' activity choices. The sport sector has an angle of 120°. How many students chose sport?
Key: 1 symbol = 4 students. Chocolate flavour has 5 symbols. Vanilla has 3 symbols. How many more chose chocolate?
Enter up to 5 labels and values, then draw the chart.
Enter 5 data points (comma-separated) to draw a line graph and find the range.
Enter numbers separated by commas. See their frequency table.
Use the tables below to answer each question.
| Sport | Frequency |
|---|---|
| 1 – Football | 15 |
| 2 – Basketball | 8 |
| 3 – Tennis | 12 |
| 4 – Swimming | 10 |
| 5 – Other | 5 |
| Age | Frequency |
|---|---|
| 1 – 10 years | 12 |
| 2 – 11 years | 18 |
| 3 – 12 years | 15 |
| 4 – 13 years | 9 |
| 5 – 14 years | 6 |
Use the bar chart data below to answer each question.
| Month | Books |
|---|---|
| 1 – January | 5 |
| 2 – February | 8 |
| 3 – March | 12 |
| 4 – April | 7 |
| 5 – May | 10 |
| 6 – June | 6 |
| Height | Students |
|---|---|
| 1 – 120–130 cm | 4 |
| 2 – 130–140 cm | 9 |
| 3 – 140–150 cm | 12 |
| 4 – 150–160 cm | 7 |
| 5 – 160–170 cm | 3 |
Temperature over a week: Mon=12°, Tue=15°, Wed=18°, Thu=16°, Fri=20°, Sat=22°, Sun=19°.
Key: 1 symbol = 4 students. Ice cream flavours: Vanilla = 3 symbols (12), Chocolate = 5 symbols (20), Strawberry = 2 symbols (8), Mint = 4 symbols (16), Lemon = 1 symbol (4). Total = 60.
A pie chart shows 360 students' after-school activity choices. Sector angles: Sport=120°, Art=90°, Music=72°, Drama=54°, Science=24°.
Mixed data and charts questions. Use the data from all the exercises above.
Harder data and charts problems.