You can virtually always communicate in English, but you may well need to be able to read Arabic numbers. Here they are. Note: The first line shows the printed versions; the second demonstrates the handwritten ones.
Pronunciation Note: Qatar is not pronounced as KAY-tar, or KWAY-tar, or even 'catarrh'. Arabic has a very gutteral voiced consonant that has no equivalent in English and is usually -- rather badly -- transliterated as 'q'. A much closer approximation of the proper pronounciation is 'cutter' or even 'gutter'. The other options above that are commonly used in English are objectionable. And 'catarrh' is frankly laughable