Work with the example
Which cell in this doubled-quantity column stopped calculating? A5:A7 contain 3,4,5. B5 and B7 calculate quantity×2, but B6 stores a fixed 8. C uses ISFORMULA to check the actual cell structure, not its displayed number.
| Row | B result | ISFORMULA |
|---|---|---|
| 5 | 6 | TRUE |
| 6 | 8 | FALSE |
| 7 | 10 | TRUE |
Edit the working cells
Change A6 from 4 to 7: B6 stays 8 and C6 staysFALSE. Repair B6 with =A6*2. It becomes 14 and C6 becomesTRUE. A fresh A6=0 then gives numeric 0 with C6 stillTRUE. Column D contains labelled text descriptions of the expected formulas, not extra calculations.
Check the failure case
At baseline the fixed 8 equals the correct calculated answer. Comparing displayed numbers misses the lost formula. Do not replace ISFORMULA with a painted TRUE/FALSE label, or assume Excel’s selection menus were exercised here.
After repairing B6, does a displayed 0 mean the formula is missing?
Show the worked answer
No. With A6=0 the live formula returns 0, and ISFORMULA remainsTRUE.