You can sum a series of numbers in Microsoft Excel manually by typing in a simple formula, or automatically with a tool.

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.

SUM is the spreadsheet equivalent of an open invite: it welcomes everything into the total, whether it belongs there or not.

You can't use a SUM() function to sum a filtered list, unless you intend to evaluate hidden and unhidden values. Here's how to sum only the values that meet your filter's criteria.