--- title: "Frequency tables, bar charts and pie charts" description: "Construct and interpret frequency tables, bar charts, pie charts, pictograms, and vertical line charts for both categorical and grouped numerical data, choosing appropriate representations for the dat" canonical: https://lightmysky.com/learn/mathematics/frequency-tables-bar-charts-and-pie-charts-mt_eKJG-0eC6D source: https://lightmysky.com/learn/mathematics/frequency-tables-bar-charts-and-pie-charts-mt_eKJG-0eC6D.md retrieved: 2026-09-02 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # Frequency tables, bar charts and pie charts Construct and interpret frequency tables, bar charts, pie charts, pictograms, and vertical line charts for both categorical and grouped numerical data, choosing appropriate representations for the data type Subject: Mathematics · Area: Data & Statistics · Ages 11 to 13 Page: https://lightmysky.com/learn/mathematics/frequency-tables-bar-charts-and-pie-charts-mt_eKJG-0eC6D ## Ready when they can - Construct a grouped frequency table from raw continuous data, choosing appropriate class intervals - Draw a pie chart by calculating the angle for each category - Interpret a bar chart comparing two data sets and draw a conclusion about the difference ## Lesson: Choosing and drawing the right chart Not every set of data fits the same chart. Categories, like favourite drinks or types of pets, work well as bar charts, pie charts, or pictograms. Numbers that can take any value, like height or time, need extra work first: you group them into class intervals before you can chart them at all. *(drawing: City A had 10 rainy days and City B had 6. The taller bar tells you which city had more rain, and the gap between the bars shows you by how much.)* Reading a bar chart is a two-part job. Read each bar against the scale to get its value, then subtract the smaller from the bigger to say how much more one group has. **Example.** A class of 20 students voted for their favourite drink: tea 5, coffee 3, juice 8, water 4. To turn each vote count into a pie chart angle, divide it by the total and multiply by 360. Juice got the most votes, so 8 divided by 20 times 360 equals 144 degrees, the biggest slice of the circle. When you group continuous data, like the heights of 30 plants, keep every class interval the same width and make sure they don't overlap or leave gaps. Around 5 to 8 groups usually keeps the table clear. Too many groups hides the pattern; too few hides the detail. To pick a width, take the range, divide by how many groups you want, and round up so every value still fits. **Recap.** Match the chart to the data: group continuous numbers into fair class intervals, share out a pie chart by angle, and read bar heights carefully before you compare them. ## Practice 14 questions on this page, each with its working shown. ## Needs first - [Line graphs (age 10+)](https://lightmysky.com/learn/mathematics/line-graphs-age-10-mt_bESTSBB0wK) - [Reading tables](https://lightmysky.com/learn/mathematics/reading-tables-mt_Cqm8iy48UI) - [Statistical Analysis Vocabulary](https://lightmysky.com/learn/mathematics/statistical-analysis-vocabulary-mt_fmm-P17Vka) - [Percentages (age 12+)](https://lightmysky.com/learn/mathematics/percentages-age-12-mt_iEXqN48w3x) ## Opens up - [Comparing measurements](https://lightmysky.com/learn/mathematics/comparing-measurements-mt_XSXnTQoQ4l)