Gender reveal ideas!

I need some help! My family is too far to do a fun gender reveal party, but my students very much want one! I teach 8th grade ad have 122 students split up in 4 classes (2 are back to back) so I need something fun, but that is easy and inexpensive enough with all of them and not a lot of clean up between classes. I wanted to do cupcakes but I don't think I have the patience or energy to make that many cupcakes anymore lol. I find out in a month so I'm trying to plan it now! I wouldn't mind taking my classes outside either so that's an option!