Hebrew also has the letter ˁain and it is universally transcribed with the sigla ˁ (as it is done in A. S. Tritton's Arabic [Teach Yourself Arabic]) and so it's very odd to transcribe it with the number 3. It's as if the beta version of DL Arabic was done by complete amateurs without basic understanding of Semitic language transcription sigla. My understanding is that it's pronounced as a glottal in the throat (although that is no longer the case for modern Hebrew except for some sephardic Jews influenced by Arabic, which is actually more closely approximates the original pronunciation of Hebrew ע). For the next version of Arabic DL, you might consider getting rid of the 3 and replace with ˁ
I'm not sure that should be the case, I've seen the 3 being used highly consistantly on other pages besides Duolingo. For me, it seems the standard way of transcribing it. Also, that symbol is highly impractical to write on computer or android and people used to modern Hebrew would'nt be familiar with it, so the set of people actually helped with that would be highly restricted.
OK. Thank you. I've toned down the emphatic statement. It's definitely a thing in Arabic to sometimes use 3, it appears, but I'm pretty sure in academic circles the siglum is typically ˁ. But I'll keep an eye out as I progress in Arabic and am grateful for your help.