This is called "Grouping Sheets" if you want to look in help
or refer to the process.

A word of WARNING about Grouping Sheets. Any change you make
to the sheet you see will be made to all of the grouped sheets. So as
soon as you are finished printing or working with grouped sheets,
be sure to Ungroup the sheets, by selecting a single sheet, or by
right click on a sheet tab and selecting "Ungroup Sheets". Think
of failing to ungroup sheets as failure to see the "Severe Tire Damage"
signs where you are not to back up for any reason.
---
HTH,
David McRitchie, Microsoft MVP - Excel
My Excel Pages: http://www.mvps.org/dmcritchie/excel/excel.htm
Search Page: http://www.mvps.org/dmcritchie/excel/search.htm

"Rasoul Khoshravan" wrote
1- First you have to set the page one of all 80 sheets.
This could be done by clicking sheet 1, holding shift key and then clicking
sheet 80. Now all your 80 sheets are selected (sheet tab's are white). [...clipped...]