Shift+F9 will calculate only the active sheet. From the
XL Help for XL2003:
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Press F9 Calculates formulas that have changed since the
last calculation, and formulas dependent on them, in all
open workbooks. If a workbook is set for automatic
calculation, you do not need to press F9 for calculation.
Press SHIFT+F9 Calculates formulas that have changed
since the last calculation, and formulas dependent on
them, in the active worksheet.
Press CTRL+ALT+F9 Calculates all formulas in all open
workbooks, regardless of whether they have changed since
last time or not.
Press CTRL+SHIFT+ALT+F9 Rechecks dependent formulas, and
then calculates all formulas in all open workbooks,
regardless of whether they have changed since last time
or not.