Piastres not in use in Ontario

5 dollar/piastres note, 1839 - Bank of Canada Museum

I was speaking to a store clerk in French today and I used the term "10 piasse" (Ten dollars) and she blinked a little and corrected me to 'dix dollars' - I thought about it and realized I only heard piastres in Quebec (I haven't spent much time further east so I cannot say if it is in use in New Brunswick.) After looking a little on the internet, I see that "piastres" was on dollar notes issued by banks in Lower Canada and Quebec in the 19th century, and the word comes ultimately from the Spanish 'peso'. The Spanish had found large amounts of silver in the Americas and their coinage dominated much of the world - even the Japanese yen derives from Spanish and Mexican coins that were in circulation in Asia.
Update - I did hear a bank clerk use 'Piasse' recently in Ontario, so my informant was wrong.