When
you read a price, the word "dollar" (or substitute any type of
currency) comes after the amount. e.g. "This pineapple costs four
dollars."
When writing a price symbolically, I say you should follow the same structure as when spoken. Thus, "This pineapple costs 4$."
The
traditional way of writing said sentence would be, "This pineapple
costs $4," which would logically be spoken, "This pineapple costs
dollars-four," and we obviously don't speak like that!
There
are lots of illogical things in the English language, and I'd be
inclined to let this particular one slide, except that it introduces
even more complications when working with big numbers.
Consider the following sentence: "The construction is projected to cost six-hundred-million dollars."
Naturally,
you don't want to have to write out all those words, so numerals and
symbols come to the rescue! A newspaper might write out that sentence as
"The construction is projected to cost $600 million." Now, because of
the grouping of numbers and the separation of the word million, it is
very easy to misread that sentence as "...to cost six-hundred
dollars...million...Oh, I mean six-hundred-million-dollars." Having to reread a sentence is a minor
inconvenience, but becomes more than an inconvenience when you're only
skimming the sentence, just see the numbers (because they are logically
grouped and also larger than your typical letters, they stand out) and
get a completely inaccurate notion of the real price. All this
trouble could be avoided entirely by reordering the words to "600
million $"—a bit odd-looking, but only because you're not used to that
construction.
I've been annoyed by this
backwards representation of numbers enough times that I vowed to do
something about it. Granted, I have little clout in the evolution of
language, but I will still try to make a contribution! You don't have to
follow my system, but if it makes sense to you, maybe you should! It
only takes a spark to get a fire going. Maybe, one day, everyone will
follow this syntax...but until then, at least you know why I do.