I am in the throes of submitting some book chapters that are due by the end of the week, and this struck me: I was reporting that in the U.S. about 7,000 people die every year from medication errors. I found this statistic on the Agency for Healthcare Research and Quality Web site, and when I cited it in my paper, I automatically changed it to "approximately." Then I thought of our discussions here about keeping it simple. I believe I have been brainwashed by academe!
But more importantly, is there a difference between "about" and "approximately?" I think not, but I thought I'd ask experts.
Of course, there are many ways "about" can be used in which "approximately" wouldn't do at all. "I went about my business".
But in those case in which either might do, I tend to use "about" when the exact number isn't known, and approximately when it is, but precision isn't needed.
There are about 10,000 bottles of wine in my cellar. (I haven't counted recently.)
The library, which keeps very good records, reported that it had added approximately 10,000 new titles during the last fiscal year.
There is a prescription, reported in Merriam-Webster's Dictionary of English Usage, that approximately should be replaced by about or nearly or almost when it can be. MWDEU notes that approximately is usually used in technical or reference works, and in serious general prose, and it almost never used in casual or informal contexts. They don't see any reason to avoid approximately in the contexts it is used in.