Excel formula help

Hi!

I am creating an excel payroll workbook that will have a sheet for each pay period to calculate payroll, points earned etc.  

Essentially I want to be able to pull info from a previous sheet (automatically) so it can be added with info on the following sheet.

EX:

I want to take the #from field a10-sheet 1, and add it with field a 9 - sheet 2, to get a new total in fiald a10 - sheet two.   then, I want to take the #from field a10-sheet 2, and add it with field a 9 - sheet 3, to get a new total in fiald a10 - sheet 3.   then, I want to take the #from field a10-sheet 3, and add it with field a 9 - sheet 4, to get a new total in fiald a10 - sheet 4.   and so on.  thanks so much!