I was taught that generally numbers in Japanese should be read as:
123 => ひゃく にじゅう さん
However, I was wonder if there is any case where the numbers are read one-by-one, like:
123 => いち に さん
I was thinking maybe for license plate numbers and room numbers, but I am not sure which method would be appropriate. If both are used, is there a connotation to using one pronunciation over the other?
The first case is generally used for numbers representing quantity or amount like:
price, age, weight, distance, time
The second case is generally used for numbers representing identifier like:
phone numbers, license plate, room numbers
The difference between two cases is importance of number of digits, I think so.
Rarely, the second case is used for informing any numbers that is very important. For example, military affairs.
Room numbers for sure, another example I thought up of is phone numbers. Phone numbers are primarily spoken in just digits. PIN codes and the like are also spoken in just digits, sometimes people will use a word to help remember the digits. e.g. 8931 (は・く・さ・い)
