Work with the example
Why does 1.2 plus 1.2 appear to give 2.5? A5/B5 each store 1.24 metres but show one decimal. C5 adds their full stored values; D5 explicitly rounds each first. The two-decimal row exposes the same source and total.
| Cell | Stored or calculated | One-decimal display |
|---|---|---|
| A5/B5 | 1.24 each | 1.2 each |
| C5=A5+B5 | 2.48 | 2.5 |
| D5 rounded alternate | 2.4 | 2.4 |
Edit the working cells
Change A5 to 1.26: the view shows 1.3,1.2,2.5; C5 really is 2.50 and D5 is 2.5. Fresh reset A5=1.24 and change only A5:C5 format to 0.00:1.24,1.24,2.48. Stored values are unchanged. Do not enable a setting that calculates with displayed precision for this exercise.
Check the failure case
Typing the displayed 1.2 over each source changes the sum to 2.4. Formatting is a view; ROUND is a deliberate arithmetic operation. Inspect the underlying values before deciding the total is faulty.
Does changing C5’s format from 0.0 to 0.00 change 2.48?
Show the worked answer
No. It only reveals the second decimal in the same numeric result.