This is how they say it. 4x2=8 "Quattro per due fa otto." Period. Of course if you wanted, you could paraphrase it in other ways and be understood. In AmE, I would say *"Four times two equals eight," but I'd understand you if you said "Four multiplied by two is eight," or something similar.
I have recently commented on a similar thread where the problem is that DuoLingo accepts 'is' but not 'makes' when using 'fa' as the verb. There is an inconsistency in whether DuoLingo expects literal translation or rendering of the statement in readily understood English. I put 'equals' here (although that would be 'uguale' as I have been taught in my basic Italian evening class) and was quite surprised it was accepted when the literal 'makes' is not.