FYI 2600 and 2.6k use the same number of characters.
Where I was taught…
2600 has 2 sd
2600. Has 4 sd
2.6e3 has 2sd
2.60e3 has 3 sd
Edit. If I had been in charge of setting sd rules, I would’ve said …
2600 has 4 sd
260? Has 3 sd
26?? Has 2 sd
The fact zeros are overloaded (they can be placeholders or they can actually mean 0) is confusing to students.
Since he thought people would assume it was a rounded figure, he reported it as 29,002. And is therefore known as the man who first put 2 feet on the top of Everest.
Using different number formatting instead of word or sign (~) is still implicit and not explicit.