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

How to Do the Sum of an Indefinite Series in Excel. The Microsoft Excel program includes a variety of mathematical formulas that you can apply to any cell in a spreadsheet.

To calculate the sum of squares using Microsoft Excel, you need to input a specific formula into the formula bar of the cell you're working with.

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.