Skill: Interpret circle graphs

A circle graph shows how one whole is divided into categories. A larger sector represents a larger fraction or percentage of the whole.

To find a category’s amount:

1. Find the total amount.
2. Change the category’s percentage into a fraction or decimal.
3. Multiply by the total.
4. Compare the amounts or sector sizes.

Example: A circle graph shows the favorite sports of $(40)$ students:

• Soccer: $(50\%)$
• Basketball: $(25\%)$
• Swimming: $(15\%)$
• Tennis: $(10\%)$

How many students chose soccer and basketball?

For soccer, $(50\%=\frac{1}{2})$:

$$\frac{1}{2}\times 40=20$$

So, $(20)$ students chose soccer.

For basketball, $(25\%=\frac{1}{4})$:

$$\frac{1}{4}\times 40=10$$

So, $(10)$ students chose basketball.

The soccer sector is larger because $(50\%>25\%)$, and $(20>10)$. Therefore, twice as many students chose soccer as basketball.