Skill: Create circle graphs informally

A circle graph shows how categories make up one whole group. The entire circle represents $(100\%)$ of the data. Each sector, or slice, represents one category.

To create one:

1. Find the total number of items.
2. Write each category as a fraction of the total.
3. Check that the fractions add to $1$, or $(100\%)$.
4. Draw the circle and divide it into familiar parts, such as halves, fourths, or eighths.
5. Label each sector.

Example: A class records its favorite fruit.

Fruit	Number of students
Apples	12
Bananas	6
Oranges	3
Grapes	3

Step 1: Find the total.

$$12+6+3+3=24$$

There are $(24)$ students, so the whole circle represents $(24)$ students.

Step 2: Find each category’s fraction of the total.

• Apples: $\frac{12}{24}=\frac12$
• Bananas: $\frac{6}{24}=\frac14$
• Oranges: $\frac{3}{24}=\frac18$
• Grapes: $\frac{3}{24}=\frac18$

Check the total:

$$\frac12+\frac14+\frac18+\frac18=1$$

So all the students are represented.

Step 3: Draw and label the circle.

• Divide the circle into two equal parts. Label one half Apples.
• Divide the remaining half into two equal parts. Label one of those fourths Bananas.
• Divide the last fourth into two equal parts. Label the two eighths Oranges and Grapes.

The apple sector should be the largest because $\frac12$ is greatest. The orange and grape sectors should be equal because both represent $\frac18$ of the class.