Why do some people pronounce the number 0 (zero) oh (O) as on the alphabet example 233030 is pronounced two three three oh three oh instead of the zero they say oh is it formal?

Using "oh" instead of "zero" when pronouncing numbers like 0 can be informal or a matter of personal preference. It can help to differentiate the number from the letter "O" in spoken communication or simply be a habit individuals develop. In more formal contexts, it is generally recommended to pronounce 0 as "zero" to avoid ambiguity.