"Can you give me a bowl?"
I'm trying to figure out when it's appropriate to use 碗 VS 腕子. As of writing this, this question accepts "你可以给我一个碗吗？" but rejects "你可以给我一个碗子吗？". I was under the impression that 腕 was used to refer to bowls as measurements-- e.g. "A bowl of beef noodles"-- and 碗字 was used to refer to bowls as objects in and of themselves. Is this an instance of Duolingo screwing up, or is there an underlying grammatical rule I'm missing?