Same Digits, Different Habits
Numbers are taught in the first week of every English course, and they are still one of the most common reasons for misunderstanding years later. The reason is simple: native speakers rarely say a number the way a textbook writes it. They cut it into pieces, and which pieces they choose depends entirely on the situation.
Years are the clearest example. Nineteen eighty-five is normal for 1985, because speakers break the year into two pairs. After the year 2000 the habit changes: people say two thousand, two thousand and five, and then return to pairs with twenty twenty-six. If you say one thousand nine hundred eighty-five, everyone will understand you, but nobody will say it back.
Phone numbers work the opposite way. They are read digit by digit, with a short pause where the groups end, and the number zero is often pronounced as "oh." A double number may be shortened too, so 5566 can become "double five, double six" in British English. When you give your own number, slow down at the pauses rather than at every digit.
Prices drop the word dollars in ordinary speech. A tag showing $1.99 is read as "one ninety-nine," and $250 in a shop is usually "two fifty." Context tells everyone whether two fifty means two dollars fifty cents or two hundred fifty dollars, which is why asking "two dollars fifty?" is a completely normal way to check.
A few places keep their own rules. Hotel rooms are read in pairs, so room 1204 is "twelve oh four." Sports scores use "to" as in "three to one," and a tie is "two all" or "two–two." When a number really matters, do not guess. Say "Sorry, can you give me that one digit at a time?" and the other person will slow down immediately.