Functions perform a mathematical calculation on a range of cells in Excel. The most common Functions are SUM, AVERAGE, COUNT, MIN, and MAX.

Each accepts up to 255 values in a comma-delimited list enclosed in parentheses and preceded by the name of the function. You can mix cell references and numbers, including null and zero values.

Excel has over 475 formulas in its Functions Library, but we've selected the most popular, from date and time functions to mathematics and simple data manipulation.

Save this for the spreadsheet jocks in your office—we'd bet even the experts don't know all of these formula tips.

Microsoft Excel's new FILTER() function is a great tool for reporting and dashboards. We'll show you how to use it to get more done.

You can subtract numbers in Microsoft Excel in a few different ways, depending on your data and formatting.