Actually, no. RMB is for Ren Min Bi. It is the name of the currency of PR China. And Yuan is the name of the unit of RMB. So, you can say "it costs 5 Yuan", but can't say "it costs 5 RMB". Most of the other currencies use a same word for both currency and its unit, like Dollar and Peso.
Not taught what it is before being asked!! Chinese course went from so overly simplistic on greetings to the point of being boring straight to too difficult as you are asking me what has not been shown - would love to get into this so please provide some balance..! Thanks...!!
Is yuan used specifically for currency? I work in a hotel and I am trying to learn the language to improve guest relations/experience and want to say the room number.
Example: for room 312 would I say "sānbăishíèr yuán," or would I exclude the yuán? On the notes it says currency, but elsewhere I see it as "unit."
These discussion threads are for questions/comments about the particular Duolingo exercise. Your question would be more appropriately asked in the main Duolingo forum (click "Discussion" on the menu on the duolingo website) or somewhere like the Chinese Langauge Stack Exchange: https://chinese.stackexchange.com/