How do I ask a guy to a dance?

Ugh I wish the girl in my science class that I like would ask me out lol. But yea catch him before or after class. If its the last period that just walk next to him out of class and start some convo about break or something like that. And work your way into the dance. Hope that can help you out. ;] if so I'd be glad to hear about your success!

Yeah you need to ask about it, before another girl does, usually is a good time is before class or after class, just don't be to afraid when you talk to him, that you forget to ask him about the dance, you could start out with is you have good plans you doing for your vacation and say well you know that there is this dance after vacation would you like to go with me, and things will be ok after that, then he will know you are interested and hopefully he doesn't have a date and say yes to you, so I hope for the best for you and good luck!

Definitely start talking about something else and then move on to asking him. That is a really good idea. Be casual about it. And by the story you've told, it sounds like he'll say "yes"!