This is an enhancement request for the subtotals tool (Data->Subtotals) to support inserting subtotal functions that exclude hidden rows from their calculations.

The subtotal function (not tool) uses a number sequence to define which subtotal action to perform (1=avg, 2=count, 3=counta, etc...).  They also have alternative codes that tell the subtotal function to exclude any hidden cells in the affected range.  These codes are the same numbers+100 (101=avg, 102=count, 103=counta, etc...).  They're defined in http://docs.oasis-open.org/office/v1.2/os/OpenDocument-v1.2-os-part2.html#__RefHeading__1018580_715980110

Users typically use the subtotal tool to sort their data and automatically insert subtotal rows which use the subtotal function.  It would be nice to have a simple checkbox in the subtotal tool dialog to tell the tool to insert the alternative "100-level" subtotal functions.  Then users could simple hide certain rows to have them automatically removed from their totals.

Note that bug 93171 keeps these 100-level subtotal functions from recalculating properly.