Will not go into all the other
uses for these words, just enough to highlight the difference in
use between them.
“About” is a word that means reasonably close to. About means
reasonably close to, it is a guess or an estimate. We can use it
to talk about quantity. About does not stress the closeness to
accuracy that approximately does.
“Around” also means reasonably close to. We also use around in
casual informal situations. We can use around with numbers and
quantity as we did with about. We use this for time as we saw
with the word, about. So, for time, we can say, “I will be there
around 7:00 p.m.” “I will be there around breakfast time.”
The difference between about and around is largely a matter of
preference: about is more common in British English and around
in American English.
“Approximately” means reasonably close to something else so we
use it, again, to make an estimate, to make a guess. However,
approximately is usually used in more formal situations. It is
more natural to use approximately in formal situations. If you
use “approximately” in an informal situation, it might sound
strange.
Approximately has fairly limited uses. Around and about,
however, have a few other functions to consider. When you are
making guesses, when you are making estimates, especially for
quantities or time, in most cases, about and around can both be
used.