For numbers between 1000 and 9999 is it proper English for the word "hundred" to be used? For example is it necessarily wrong to say "eleven hundred" when referring to 1100?
The number "1100" may, depending upon context, most reasonably be read as "eleven hundred", "one thousand one hundred", "one one zero zero", depending upon what it represents. Some things are typically counted in groups of 100 (e.g. years), and some things that appear to be a single number actually represent the concatenation of two numbers [e.g. street addresses in the US combine a block number with two digits that identify an address within a block] or four numbers [e.g. digits of a "telephone number"].
If a four-digit number is written with a comma between the hundreds and thousands place, it should almost generally be read by describing the number of thousands, and the number of things beyond that [e.g. 1,234 is one thousand, two hundred, and thirty four], except as noted below. For numbers without commas, I would suggest the following [N is 1-9, X and Y are 0-9; HH are 11-99; excluding multiples of ten, and II are 10-99]
0000 -- zerozero, zerozero 000N -- triple-zero N 00N0 -- double-oh-N-zero 00NX -- double-oh-N-X N000 -- N thousand N00M -- N thousand M N0II -- N thousand II or ten/twenty/thirty/etc. II HH00 -- HH hundred HH0N -- HH oh N HHII -- HH II
Note that leading zeroes generally only make sense for things like phone numbers. The other formulations are applicable to years and addresses as well, and the N000 and HH00 are suitable for use when counting things whose counts multiples of 100.
For numbers that represent counts of things (but do not represent calendar years like 1980 or 2014), it is reasonable to use the two-digits-plus "hundreds" form of counts if all other counts with which it might logically compared are only expressed to two significant figures. If bins have 450, 1,100, 2,000, and 5,700 items, they might be read as "four hundred fifty, eleven hundred, two thousand, and fifty-seven hundred". If, however, the quantities had been 453, 1,100, 2,017, and 5,706, then they should be read as "four hundred fifty-three, one thousand one hundred, two thousand seventeen, and five thousand seven hundred and six". Even though the second number happens to be a multiple of 100, it should be expressed in the same form as the others.
British English doesn't go above 1999 for the "hundreds" format. You can say nineteen-hundred, but not "twenty-one-hundred".
Years are different, and I'd expect the year 2147 to be said as "twenty-one forty-seven". But the number 2147 would never be said that way: it's always "two thousand one hundred and forty-seven" (and note the and there; that's never omitted in BrE). Even with years, it's still not entirely settled whether to pronounce a year like 2010 as thousands or hundreds.
The CBS production The 4400 is currently showing on British TV. It's pronounced "forty-four hundred" and that phrase is used extensively in dialogue to the extent that it's unimaginable to say anything else. But in a British sentence like "There are 4400 Smarties in the jar" it would definitely be thousands, not hundreds.
Context matters, and seems missing from the question. I’d suggest that “hundreds” flows from years pronounced this way. 1776, the year, is pronounced “seventeen seventy six” and 1800 would follow the same pattern, going with “eighteen hundred” and not “one thousand eight hundred”. Even for a box of 1,235 buttons, I’d imagine a student using the ‘year’ pronunciation and saying “twelve hundred.....”.
The truth (to me) is that as long as the listener understands what you mean, either way is fine.
Note that military time never uses thousands.
Regular Time / Military Time / Military Pronunciation
8:00 p.m. / 2000 or 2000 hours / "Twenty hundred hours"
11:00 p.m. / 2300 or 2300 hours / "Twenty-three hundred hours" Google.
Military usage, as agreed between the United States and allied English-speaking military forces, differs in some respects from other twenty-four-hour time systems:
Hours are always "hundred", never "thousand"; 1000 is "ten hundred" not "one thousand"; 2000 is "twenty hundred" not "two thousand". Wiki
2300 is pronounced as: "twenty-three hundred hours" or "twenty-three hundred hours" or "two-three-zero-zero hours" or "two-three-oh-oh hours" time.unitarium
I believe there is a typo in the last explanation, since the first two are identical. One should be probably be "twenty-three-zero-zero hour" (singular):
That evening I was scheduled for a twenty two thirty take-off and twenty three hundred hour rendezvous with the Thunder Six One flight. Jud McLester; Thru a Pilot's Eye
“Ma'am I will have my men check on things and get back to you, say around twenty three hundred hour at the ranch? K. Brockwell; *Have You Seen Charlie?.