Anime question

I am becoming better versed in the jargon of anime fandom, but there's one thing that's been puzzling me. So, readers-in-the-know, help me out here.

When you're saying a pairing out loud, do you pronounce the "x" at all? If I were to speak about Daniel/Jonas, I'd just say "daniel jonas" -- the slash is silent. How about if I were talking about 13x5? Is that just "thirteen five" or am I missing a vital part of the phrase? And how about the "+" in 3+4?

I have to make sure I know these things so I never look dumb. *g*

Oh my god, it just occurred to me that maybe everyone else in fandom is saying "daniel slash jonas" and I already look dumb!