When counting unique values in Microsoft Excel, use UNIQUE() as a helper function and avoid more complicated expressions.

You can sum cells across multiple sheets in Excel. This article presents steps for Adding single-cell values or Adding values in the range of cells.

Click "Values" in the Paste section to prevent Excel from changing the original formatting. Click "Add" or "Multiply" in the Operation section to add or multiply the base value to each selected value.

Filters are great tools, but you can't remove specific items from the results. When you need to do this, try Find All in Excel instead.

If you wish to count the same or duplicate values in a column only once in Excel or the count of occurances of duplicate values, read this article.