How to Find the Average?

The formula

Average = (Sum of all values) ÷ (Number of values)

Worked example: Find the average of 4, 8, 15, and 13.

1. Add them up: 4 + 8 + 15 + 13 = 40
2. Count them: there are 4 numbers.
3. Divide: 40 ÷ 4 = 10

So the average is 10.

Another example — test scores of 85, 90, and 95

• Sum: 85 + 90 + 95 = 270
• Count: 3
• Average: 270 ÷ 3 = 90

Average vs. median vs. mode: "Average" usually means the mean, but there are three related measures:

• Mean — add everything up and divide by the count (what we did above).
• Median — the middle value when the numbers are sorted in order.
• Mode — the value that appears most often.

Why it matters: The mean can be skewed by outliers. For example, in the set 1, 2, 3, 100, the mean is 26.5 — which doesn't represent most of the data well. In cases like that, the median (2.5) gives a better sense of the typical value.

Quick tip: In a spreadsheet like Excel or Google Sheets, use =AVERAGE(A1:A10) to calculate it automatically.

Nearby questions in this topic include How to Find the Hypotenuse of a Triangle? and How to Find the Perimeter of a Triangle?.

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