It isn't nonsense. 7/2 represents a real number. You can round a real number up or down. So you can round 3.5 to 3. 7/0 doesn't represent a real number. It doesn't even make sense to do anything to an undefined number.
All rational numbers are real numbers.
> Why not a complex number?
What?
> That you especially like the real numbers is particularly unfortunate
It's not a matter of me liking or disliking real numbers. It's just that the topic at hand is about real numbers.
> when they are so poorly represented in essentially all programming languages.
Not essentially all programming languages. In every single one. It's the nature of real numbers. It's also not just 'programming languages', it's hardware as well.