A random number, with a tiny bit of ceremony
You could ask Siri. You could roll a d10. Or you can hit spin and watch a wheel land on your number with a cheer. All three work. This one is more fun to show on a stream, in a classroom, or when you need to pick a hole in a trivia card. The visual spin gives the result weight — "the wheel chose it" is harder to argue with than "the computer chose it."