Which average answers your question?
An average is a summary chosen for a purpose. Before calculating one, decide whether every observation should have equal influence and whether the dataset is complete.
The mean shares the total equally
For 2, 3, and 10, the total is 15 and the arithmetic mean is 5. Think of redistributing the total equally among the three observations. Every entered value has equal influence. This can describe an overall amount, but one unusually large observation can move the mean a long way from the values that occur most often.
The median finds the middle position
Sort the values first. The middle of 2, 3, and 10 is 3. With an even number of values, take the average of the two central ones. A median can give a different perspective when a list is skewed or contains a large outlier. It does not explain why that outlier exists, and it does not authorize removing the observation from the source data.
Weights change the question
If one assessment is worth 20% of a course and another is worth 30%, their scores should not be averaged as if both carried the same share. Multiply each score by its weight, add the contributions, and divide by the sum of entered weights to get an average over the assessed work. Daykit shows that normalization explicitly rather than hiding the weight total.
A partial course result is not a final grade
A score of 80% at a 20% course weight contributes 16 points. A score of 70% at a 30% weight contributes 21, for 37 course points over half the course. The assessed average is 74%, but another 50% of the course is still unentered. Calling 74% the final result would ignore the remaining assessments. Calling 37% the assessed average would treat unentered work as zero.
Standardize the inputs
Use one unit for a numerical list. In the average calculator, commas separate values and decimal points mark fractions. In the grade calculator, scores must already be percentages; a raw score of 18 out of 20 becomes 90%. Keep grade weight separate from possible points. A test with more questions does not necessarily have a larger course weight.
Use the official rules when they apply
Institutions may drop a score, apply a minimum examination requirement, scale a result, or round at a specific stage. A general calculator cannot infer those rules. Use these tools to check arithmetic and understand how a result was formed, then verify it against the documented course policy and official record. A useful summary includes its assumptions, not only a single number.
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