Fixing typos usually results in changing a character or very few. When trying to fix such typos (on other people questions), I get a message that the change is too short.
I bypassed that problem by adding some more characters and deleting them in another edit but it seems like a hack. It seems that I also cannot revert to the previous version so 3 rounds are needed.
How should typos be fixed?
In general you should not fix a single letter typo; one exception would be if it's an important word in the title (since people search for those!). The fact that the system tries to prevent you from making very small edits is deliberate -- it tries to stop you because you probably shouldn't. The editing-privilege page says "Tiny, trivial edits are discouraged - try to make the post significantly better when you edit, correcting all problems that you observe." ... single letter edits are about as tiny as they come, so that's what it's asking you to avoid.
I posted some of those links in comments in order that you saw some of the discussion of edge cases and potential exceptions (e.g. many one-character changes in mathematics may be the opposite of trivial; the abovementioned issue with title keywords)
If you really can't see anything else that needs fixing, perhaps best to wait until you get 2000 reputation points & the privilege of making edits which don't need review, & can be of any length, rather than mess up the edit history with work-arounds. But if you look carefully, there's often something else. The idea behind the rule is to avoid the review queue's being filled with tiny edit suggestions (even though our queue's usually empty at the moment).
Please don't do minor changes, unless you can combine them with larger changes in the same post. Remember that editing a question bumps it to the top of the "active questions" list. Add this to people having to sign off on your edits until you reach the 2k rep threshold, and at some point changing "their" to "there" actually turns from signal into noise.
