New question:

I know now how to use "=sheet1!a1" to copy cells from sheet 1 to sheet 2,3
etc.

Is there is a formula that will allow me to enter data
into sheet 2, and have it copy automatically into sheet 1 and 3, or into
sheet 3 going to sheet 1 and 2? So that I can enter the data into any sheet
and have it transfer to all sheets, rather than always from sheet 1 to sheets
2 and 3.