Mathematics
Grade 8
15 min
Interpret circle graphs
Interpret circle graphs
Tutorial Preview
1
Introduction & Learning Objectives
Learning Objectives
Identify the components of a circle graph, including the title, legend, and sectors.
Determine the total quantity or 'whole' represented by a circle graph.
Calculate the numerical value of a specific category when given its percentage and the total.
Calculate the percentage of a specific category when given its numerical value and the total.
Compare and contrast different categories within a circle graph to draw conclusions.
Translate information from a circle graph into meaningful statements about the data.
Ever wondered how companies show what customers like most, or how a school budget is spent? 📊 Circle graphs are powerful tools that make understanding these proportions super easy!
In this lesson, you'll learn how to read, understand,...
2
Key Concepts & Vocabulary
TermDefinitionExample
Circle Graph (Pie Chart)A circular graph divided into sectors, where each sector represents a proportion or percentage of the whole.A graph showing how students travel to school (bus, car, walk, bike) is a circle graph.
SectorA 'slice' of the circle graph, representing a specific category or part of the whole dataset.In a graph showing a family's budget, the slice labeled 'Rent' is a sector.
Percentage (%)A way to express a proportion out of 100. In a circle graph, the sum of all percentages for all sectors must equal 100%.If 25% of students walk to school, it means 25 out of every 100 students walk.
ProportionA part, share, or number considered in comparative relation to a whole. Percentages are a common way to express proportions.If 1/4 of...
3
Core Formulas
Calculating a Part from a Percentage and Total
$\text{Part} = \left( \frac{\text{Percentage}}{100} \right) \times \text{Total}$
Use this rule when you know the total amount and the percentage for a specific category, and you want to find the numerical value of that category.
Calculating a Percentage from a Part and Total
$\text{Percentage} = \left( \frac{\text{Part}}{\text{Total}} \right) \times 100\%$
Use this rule when you know the numerical value of a specific category and the total amount, and you want to find what percentage that category represents.
Sum of Percentages in a Circle Graph
$\text{Sum of all percentages in a circle graph} = 100\%$
This fundamental rule ensures that all parts of the whole are accounted for. It can be used to find a missing percentage...
5 more steps in this tutorial
Sign up free to access the complete tutorial with worked examples and practice.
Sign Up Free to ContinueSample Practice Questions
Challenging
In 2022, a school had 500 students, and a circle graph showed 20% were in the band. In 2023, the school's total population grew to 600 students, and their new circle graph also showed 20% were in the band. What was the change in the actual number of band members from 2022 to 2023?
A.The number of members stayed the same.
B.The number of members increased by 20.
C.The number of members increased by 100.
D.The number of members decreased by 20.
Challenging
In a school election, a circle graph shows that Candidate A received 45% of the votes and Candidate B received 30%. If Candidate A received exactly 60 more votes than Candidate B, what was the total number of votes cast in the election?
A.400 votes
B.150 votes
C.600 votes
D.900 votes
Challenging
A farm has 120 animals, which are either cows, chickens, or pigs. The number of chickens is three times the number of cows, and the number of pigs is twice the number of cows. What percentage of the farm's animals are pigs?
A.20%
B.40%
C.33.3%
D.50%
Want to practice and check your answers?
Sign up to access all questions with instant feedback, explanations, and progress tracking.
Start Practicing Free