Both lower_level_thinking worksheets and too many (even high quality) worksheets can hold students back by not providing stimulus and challenge. Studies have shown for years (just do a Google search!) that children learn best through active involvement and real_life experiences. Virtually every teacher knows that children learn to read by being exposed to books and by being read to, NOT by completing worksheets. The same applies to all areas of learning.
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.