Are you referring to sheets within a workbook (Excel document), or different
workbooks? If the former, numbers 2 and 3 will change immediately if you
change a source in 1. Let's say the value in sheet 1 cell B5 is 275. If B5
of sheet 2 is set to equal B5 of sheet 1, it will update immediately if you
change 1 to 280.
But if different workbooks, they are saved with their old values until
reopened, whereupon they will either update automatically or on
prompt--depending on the setting you made for those workbooks. Generally,
it's much easier to assemble linked sheets in the same workbook because you
don't have to use external references, which are easily compromised.
