Later addition: some data from Google n-grams and just plain googling around:
The people who say "ten out of ten" are correct, but it is certainly not the only way that an English speaker would say this.
IMHO saying "ten out of ten" is most appropriate when there are 10 discrete items, e.g. 10 questions that you've got correct.
It is slightly less appropriate when answering something like a customer satisfaction survey, e.g. "how happy are you with this website, on a scale of one to 10". "I gave them ten out of ten stars", but also "I rate them ten on ten", eliding the "I gave them...stars" or "I rate them..." parts.
I was a bit surprised at how adamant people were that they knew only "ten out of ten", and that they had never heard "ten on ten", "ten of ten", "ten over ten", or "ten slash ten".
So I did what one does: look at Google n-grams, and just search the web for uses.
---++ Google n-grams
Google n-grams confirm that "10 out of 10" is significantly more common. Roughly 100X more common than "10 of 10", and 600X more common than "10 on 10", for the settings on my screen right now (American English 2019, 1800-2019).
"10 on 10" is absent in the British English corpus. Which is consistent with what some of you are saying, although I could swear it was my good old English dad who taught me "10 on 10", saying that that was how they talked about a perfect grade at his English grammar school, which was founded in the 14th century.
"10 out of 10" only started becoming relatively common circa 1920. No, I'm not that old :-)
In the very 1st query I entered, "10 out of 10" only pulled ahead of "10 of 10" circa 1980. So I was about to say "this is generational". However, although I have captured that screenshot, running the query on my iPhone, I have not been able to reproduce it on a large screen. And on the iPhone there was so much over printing and poor rendering that something might have been messed up. Plus, of course, the earlier you go for infrequent phrases, the less data. And I haven't investigated context more fully - they might have been saying "ten on ten" for some completely different reason.
It doesn't seem worthwhile posting the graphs, because you can reproduce easily at https://books.google.com/ngrams.
---++ web search
As for googling, of course "10 out of 10" is far more common.
The Urban Dictionary says "ten on ten" is "an expression used when receiving a pleasant surprise, or when one discovers something that they find remarkable." Somewhat aligned with my usage.
There are a few queries and responses where people say «I suspect that "ten on ten" is an Indian equivalent of the British (and American) "ten out of ten"». Perhaps I picked it up from Indian friends. (I'll bet many readers are not familiar with the «French style» quotation marks or guilemets.)
Apparently "M on N" is drug terminology. Doesn't apply to me.
Hey, it may not be a form you are familiar with, but it's shorter, and everybody knows that in English shorter eventually wins. Eventually. Neologisms are not just for Shakespeare! Although course I don't want to lead an English Language Learner astray.
'ten out of ten' <-- "I got ten out of ten questions correct"
'ten on ten' <-- "I rate them ten on a scale of one to ten"
and further afield:
If you have spent a lot of time reviewing documents and slide sets, you will often see at the bottom or top of the page "page M of N", e.g. "page 4 of 10" or "page 10 of 10" for the last page. Sometimes abbreviated "4/10" or "10/10".
Some have suggested that "M of N" is a short form of "M out of N", dropping the "out".
---+ ORIGINAL PERSONAL
Personally, I usually say "ten slash ten". But that's in part because my speech recognition software produces 10/10 with numbers when I say slash, but "ten out of ten" with words if I say "out of" or "on",
Canadian English speaker, US resident many years. For that matter, my speech recognition software is USA.