Identical worksheets are needed prior to using the Consolidation feature, creating a sum across worksheets or using the Paste Special Math features to create summary worksheets. By grouping the worksheets first and then adding rows or columns, changing headings and other formatting operations, you ensure that the spreadsheets remain uniform.
How many Worksheets can I Create within one Workbook? Prior to the release of Excel 2007 users could only create 255 within one workbook. However, since the release of Excel 2007 users can now create as many worksheets within one workbook as the memory of the computer can handle. Even if the user does not have access to one of the newest versions of Excel such as Excel 2007 or Excel 2010, they can still make as many worksheets as they would like, but earlier versions of Excel will require more workbooks.