A place bet on 5 is 7:5 odds (according to my cheat sheet, but may vary depending where you are). Depending on how things are going, I might buy a 9 with it. I very rarely play the field. Okay, your roll.
No math, it's gambling. If this were blackjack I would stay on the dealer's 5. I don't gamble much anymore, but have fond memories of me and my ex stumbling back to our room at dawn. That was back when we had fun and she still drank. She actually got kicked out of a casino because she was a little over the top on the intoxication scale. She liked to play slots.