It may be a regional thing. I learned English while I was in the states and we learnt “six hundred and fifteen” if you’re saying the digit-place words (hundred, thousand, etc), but “six fifteen” would also be correct. “Six hundred fifteen” was acceptable, but not preferred, and “six and fifteen” is not used.
It may be a regional thing. I learned English while I was in the states and we learnt “six hundred and fifteen” if you’re saying the digit-place words (hundred, thousand, etc), but “six fifteen” would also be correct. “Six hundred fifteen” was acceptable, but not preferred, and “six and fifteen” is not used.