Bunu İngilizce (ABD) da nasıl dersiniz? some of the great benefits of cellphones are as follows, number one.... number two....
does this make sense ?

Bir çeviriye bakın

Some of the great benefits of cell phones are convenience, safety, ease, etc.
Some of the great benefits of cell phones are as follows. (1) ---, (2) ---, (3) ---

The words "as follows" are optional. You can keep them or leave them out.
You can also leave the numbers out. Or you can use any form for the numbers that you want. But you can't mix the forms.
You can say "firstly, secondly, thirdly..."
Or you can say "first, second, third..."
Or you can say "1, 2, 3..."
But you can't say "firstly, second, third..."