Ask Marilyn: Rounding Off Numbers

Brittany Barthelmass of Mesa, Arizona, writes:

Marilyn: I've noticed that you often round numbers when you're answering a question. For example, you'll write "almost 60 percent" or "about half," etc. Why not use the exact answer?

Marilyn responds:

When I round numbers, it's usually for one or both of these reasons: (1) Round numbers are easier for readers to remember, and I believe they're interested in the general content of the answer. (2) Exact answers may be impossible to determine, and I don't want to imply that they are definitive.