How to say the digits after the decimal [closed]
Solution 1:
Formally in American English, you should either say each digit separately or identify the fraction:
one point seven five
one and seventy five hundreths
It would not be appropriate to say "one point seventy five" because seventy five is orders of magnitude larger than the decimal you're identifying.
Informally, it is unlikely anyone would be confused by saying "one point seventy five", though other numbers may cause some confusion if being heard in such a fashion.