The hegemony of software only accepting . has de facto pushed the standard everywhere for computers, but here in France I still write with a comma, but type with a dot.
A few years ago Excel and some other softwares started to be locale dependent and I never wanted to burn my computer this much
French dev currently working for a French but global client, here. The UI of the timesheet app is in English but the fields only accept `,` as decimal point. It's so needlessly confusing.
That's one of the great boons of localization. The webapp knows you're in France, so it tries to do the right thing, while giving you a US English UI. I experience the same thing, but got used to it somehow.
Another good example is how "İ" is popping up everywhere, even in English, because of misconfigured locale settings and how changing case is affected by it. We (Turks) are responsible for that, sorry (We have ı,i,I,İ =D ).
Cyprus and Peru use , for decimal point for non-currency amounts and . for decimal point with currency amount. So it's not even consisent inside some languages.
To add to the complexity of the whole situation, some countries don't separate by thousands (every three zeroes). India uses a 2,2,3 system (crore, lakh, thousand).
Petrol stations... I have no idea how widespread this practice is, but at least in Germany fuel prices have 3 decimal points to better confuse motorists. The third number is usually displayed smaller and is of course always a nine. So, if you see the price for a litre of diesel at e.g. 1.62⁹ €, you might forget to round it up mentally.
International standards say that either dot or comma is acceptable as decimal separator and thousand separators are optional spaces, typically a half space when properly typeset.
ISO 31-0 (after Amendment 2) specifies that "the decimal sign is either the comma on the line or the point on the line". This follows resolution 10[1] of the 22nd CGPM, 2003.[2]
For example, one divided by two (one half) may be written as 0.5 or 0,5.
For example, German speaking countries use a comma instead of a decimal point, whereas the latter is used as a group separator. The German word for decimal place is "Kommastelle" (= "comma place").
A few years ago Excel and some other softwares started to be locale dependent and I never wanted to burn my computer this much