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.

If you manage data in multiple Excel spreadsheets, you can use the Consolidate Data wizard to merge data from several spreadsheets or workbooks into one master sheet.

A complex Excel 2007 workbook could require multiple sheets. By default, Microsoft provides three sheets on each workbook, but you can add as many as you need.