If it is just one cell that you want to update in each sheet, then this simple formula should suffice:-
Place the same formula in each required cell in each sheet (except your input sheet, sheet1) and as the data in the cell in sheet1 updates, so will the other cells in each other sheet, instantly. I have used cell A1 as a guide so change this to suit yourself.
If there is a little more that you need to tell us, then please upload a sample of your work book showing inputs and the expected results. You can upload a sample to a free file sharing site such as DropBox, ge.tt or SpeedyShare then post the link to your file back here. Be careful with any sensitive data.