we don't say "nine hundred ninety nine" in the rest of the english speaking world

it's an american english idiom question

just ask anyone from australia or the UK or anywhere they learn english from the UK

i know how to say all the numbers in a few languages and they all have different rules about whether you use "and" or not

bulgarians (and russians) are old school, they use "и" (and) all the time when saying numbers

in english prior to the 20th century that was common in the UK as well... prior to the 19th century even the two digits had them, 4 and twenty... yes, and back to front as well...

and germans. lol. they are the oldest school of all, even russians and bulgarians use conjunctions less in their numbers

and anyhow, even if you leave them out, they are implicitly there, like ghosts