This deep dive covers Reading and Interpreting Pie Charts within Pie Charts for GCSE Mathematics. Revise Pie Charts in Statistics for GCSE Mathematics with 14 exam-style questions and 20 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 5 of 8 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Reading and Interpreting Pie Charts
Finding Values from Angles
Formula: Value = (Angle ÷ 360°) × Total
Example: Reading a Pie Chart
A pie chart shows how 240 people travel to work. The "Car" sector has an angle of 150°. How many people travel by car?
Solution:
Value = (150° ÷ 360°) × 240 = (5/12) × 240 = 100 people
Comparing Sectors
- Largest sector: Represents the modal category
- Equal sectors: Have the same frequency
- Sector comparisons: Can be made using angles or percentages
Converting to Percentages
Formula: Percentage = (Value ÷ Total) × 100%
Or: Percentage = (Angle ÷ 360°) × 100%
Practice questions for Pie Charts
A pie chart shows the results of a survey about favourite holiday destinations. The sectors have the following angles: - Beach: 144° - City: 90° - Countryside: 72° - Mountains: 54° Which destination is the modal category?
A newspaper reports that a pie chart shows Company A has a 'dominant market share' in the smartphone industry, with their sector taking up nearly half the chart. A critic argues that the pie chart is misleading. Explain two limitations of using a pie chart in this context, and suggest what additional information would make the chart more useful.