What 4 digit number will always equal 8 if you ad or multiply all the digits together?

“…Did you just make that up for me, or was that something that existed beforehand? Because it’s certainly a riddle that suits Kid~ Also… this particular riddle marathon is for me to get it wrong and you to command something for if I do… You just wanting to give riddles? Hakuba mun has reasons for not saying a command, but that doesn’t mean you can’t.”

Four numbers where in a race//they’re all a little odd but having fun anyway// the luckiest finished last while the oldest showed them how it’s done.// the youngest wasn’t the worst but they couldn’t never beat their elder.//what order did they finish in?

“Hmm… Quite the interesting one…Seven must be last, being seen as the luckiest. It seven isn’t the oldest, then that must be nine? Though… saying the youngest couldn’t never is a double negative. Don’t know if that was intentional or not, considering the youngest has to be in between two higer numbers… Unless ‘showing how it’s done’ only applied to seven, and the younger really does beat all the older numbers. With how it’s written, I’d hazard seven in last, nine in third, five in second, and three in first. Though, that said, problems come up depending on whether you use three and five, five and one, or three and one…. So many possible problems in wording… but I’ll go 7953 last to first for now.”