Please help me i need to think of a way to get $800 by May!!!

Me and the rest of my 8th grade class are going to Washington D.C. in May and the only way i can go is if I come up with $800! my parernts are already tight on money so i doubt they willl give me any and i really want to go on this trip with my friends so if you have any ways that i could get some money let me kno please thanks :)