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