As a new never-studied-Arabic-before-this-course learner, I have been incredibly confused when suddenly the number 3 appears as the "how is this pronounced" in the lessons. I'm guessing this is probably just the way things are done, but it really would be helpful to have an explanation of this. I see "3" and automatically think "three" which isn't the sound that the Arabic letter is making at all...
Since Arabic has some letters/sounds that don’t have an exact equivalent in Latinized alphabets, a number is used to represent these sounds (until, at least one learns to recognize the Arabic letter itself). The letter “Ayn” is particularly challenging to pronounce, since there is no equivalent to it in English etc; so, it’s represented by a 3, whenever it appears in a word. Ayn has four different forms: isolated, initial, medial, final ـع ـعـ عـ ع For now, this course is not teaching all the positions, but just wants you to recognize the sound by representing it with the number 3.
Here’s a YouTube link that shows you how it sounds:
If you’re interested in learning a little more about the explanations of the numbers that are used, here’s an audio link from the Arabic Language Guide, Facebook:
There’s also this chart explanation of the numbering system for sounds: