Let's say we have the number 9. We split it into three equal parts. 9/3 = 3 easy enough.
Now let's represent each part as a %.
33.3%
If we add up the 33.3% 3 times we have 99,9%. So to make it even one of the parts should be bigger than the other, but then the number 9 wouldn't be split up in equal parts.

So where does the 0,1% go?

Is this a real math problem or just an issue that comes from language?
Serious question, just wondering.