Work with the example
Which packs should enter your own page subtotal? B5:B7 are explicit numeric selectors:1 includes,0 excludes. C keeps the source page counts visible. D validates each selector and requires a numeric quantity only when that row is selected.
| Pack | Include | Pages | Contribution |
|---|---|---|---|
| PackA | 1 | 12 | 12 |
| PackB | 0 | 8 | 0 |
| PackC | 1 | 5 | 5 |
Edit the working cells
F5 checks all three D cells are numeric before SUM(D5:D7). Baseline 17. Change B6 to 1:25. Fresh B5=0 while B6=1 gives 13. Clear selected C6: D6 says Quantity missing and F5 says Check inputs. Set B6=0 with C6 still blank: that unselected row contributes 0. Selector 2 or text "1" is refused.
Check the failure case
F8 sums all source quantities and gives 25 at baseline, wrongly including PackB. Numeric selectors are not checkboxes or hidden-row filters, and the workbook does not decide an organizational inclusion policy.
Should an unselected row with no quantity block the subtotal?
Show the worked answer
No. Its contribution is 0 by the stated selector rule; selected rows still require numeric quantities.