📊 Data and Charts

Read, draw and interpret all kinds of data displays!

📖 Learn
Charts and diagrams
✏️ Examples
Worked problems
🔬 Visualiser
Build a bar chart
🎯 Practice
20 mixed questions

📖 Data and Charts

1. Tally Charts

Tally marks record data as you count. Groups of 5: ||||

|||| = 5  |  |||| | = 6  |  |||| |||| = 10

Use tally charts to collect data quickly!

2. Frequency Tables

A frequency table shows how often each item appears.

ColourTallyFrequency
Red||||5
Blue|||| |||8
Green|||3

3. Bar Charts

Bar charts use bars to show amounts. The taller the bar, the bigger the value.

Always check the scale on the y-axis — each line might be worth 2 or 5!

4. Pictograms

Pictograms use pictures or symbols to show data.

Each 🍎 = 2 apples

🍎🍎🍎 = 3 symbols × 2 = 6 apples

Half a symbol = half the key value.

5. Venn and Carroll Diagrams

Venn diagram: overlapping circles show things that belong to two groups.

Carroll diagram: a grid sorted by yes/no for two properties.

✏️ Worked Examples

Example 1 – Reading a Bar Chart

A bar chart shows books read per week. The bar for Monday reaches 5.

Read the height of the bar
Monday = 5 books

Example 2 – Pictogram (key = 2)

A pictogram uses 🌟 where each 🌟 = 2. Row shows 🌟🌟🌟.

3 symbols × 2 = 6

Example 3 – Tally Chart Total

Tally: |||| = 5. What is the frequency?

Count the marks: 5
Frequency = 5

Example 4 – Frequency Table

Table shows: cats=25, dogs=4, fish=7, birds=13, rabbits=6, other=2. Total pets?

25 + 4 + 7 + 13 + 6 + 2 = 57... Hmm, the answer for Q1 is 25 (cats)

Example 5 – Venn Diagram

Venn: Left circle (multiples of 2), Right circle (multiples of 3), overlap = multiples of both.

The overlap region = multiples of 6
Count items in the overlap to find how many are in both groups.

🔬 Bar Chart Builder

Enter Your Data (up to 5 bars)

Your Bar Chart

Exercise 1 – Read Bar Chart Values

A bar chart shows favourite pets. Read the value for each bar.

Exercise 2 – Pictogram (each symbol = 2)

Count the symbols and multiply by 2 to find the total.

Exercise 3 – Tally Chart Totals

Count each tally to find the frequency.

Exercise 4 – Frequency Table Questions

Use the frequency table to answer each question.
Table: Cats=25, Dogs=4, Fish=7, Birds=13, Rabbits=6, Other=2, Hamsters=9, Guinea pigs=5, Snakes=3, Turtles=8

Exercise 5 – Venn Diagram

A Venn diagram has Region A (left only), B (overlap), C (right only). Count the items in each region as described.

🎯 Practice – 20 Questions

🏆 Challenge