With an American lifetime of using the period as the decimal point (and two degrees in math), it's disconcerting to me to read numbers using the comma for that purpose. Is that just my American insularity? Maybe not. Here is a reference on the subject:
https://en.wikipedia.org/wiki/Decimal_mark
Countries where a dot "." is used as decimal mark include the
United Kingdom and the United States. That is the custom in India, China, and Japan, too according to my source. So it seems that most people on Earth today use the period as I do, not that I feel great compulsion to go with the majority. Just that it is convenient.