What Are Mean, Median, and Mode?
Mean, median, and mode are three ways to describe the "center" or "typical value" of a set of numbers. Each measures something different.
Mean (Average)
Add all numbers. Divide by how many there are.
Data: 4, 7, 8, 10, 11 Mean = (4 + 7 + 8 + 10 + 11) ÷ 5 = 40 ÷ 5 = 8
The mean is the "fair share", if everyone got the same amount, each would get 8.
Weakness: Sensitive to extreme values. If the data were 4, 7, 8, 10, 100, the mean would be 25.8, not representative of most values.
Median (Middle Value)
Put numbers in order. Find the middle one.
Data in order: 4, 7, 8, 10, 11 → Median = 8
For an even count, average the two middle values: Data: 4, 7, 8, 10, 11, 15 → Median = (8 + 10) ÷ 2 = 9
Strength: Not affected by extreme values. With 4, 7, 8, 10, 100, the median is still 8.
Mode (Most Frequent)
The number that appears most often.
Data: 3, 5, 5, 7, 8, 5, 9 → Mode = 5 (appears 3 times)
A data set can have no mode, one mode, or multiple modes.
Best for: Categorical data (favorite color, preferred brand) where mean and median do not apply.
Quick comparison
| Measure | What it finds | Best when |
|---|---|---|
| Mean | Balance point | Data has no extreme outliers |
| Median | Middle value | Data has outliers or is skewed |
| Mode | Most common | Data is categorical or you want the most popular |
Related concepts
- How to Teach Mean, Median, and Mode: full teaching guide
- Data and Graphs: visualizing data
- Fractions and Decimals: computing averages often requires decimal division