Excel PracticeSUM practice
A range-based total is easier to audit than a long chain of additions.
What this lesson covers
A colon includes every cell between the endpoints; a comma separates distinct ranges.
3 exercises in this lesson
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Task 1 · cell E10
Add all six order revenues.
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Task 2 · cell E10
Add all six order quantities.
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Task 3 · cell E10
Combine units from C2:C4 and C6:C7, excluding row 5.
Using SUM at work
The syntax is SUM(number1, …) or SUM(C2:C7). Once it is in your hands, the work it replaces is the kind of thing that used to mean scrolling a column and hoping you did not miss a row.
This is lesson 5 of 37. It takes a few minutes, and the exercises are marked the moment you submit rather than at the end.
Where people usually slip
- Ranges drift. Pointing at three cells when the data has six is the single most common cause of a wrong total, and it is invisible because the answer still looks plausible.
- Copying breaks a reference. Relative references shift when a formula is copied. If a value should stay put, lock it with dollar signs.
- The number is right, the method is not. Typing a total by hand produces the right answer once. A formula produces it again when the data changes, which is the actual skill.
How this is marked
Each exercise is checked against the result the formula should produce, and then re-run on a different set of numbers. A hardcoded answer passes the first check and fails the second, so it is rejected. That second pass is the part that makes the practice stick.