Even programs with the best intentions sometimes have difficulty attracting girls to STEM (Science, Technology, Engineering, and Math).
Here are some tips and tricks for balancing the gender gap for your event:
Have a female student help you make digital invitations that can be sent to friends. If a girl helps create them, they have a larger chance of appealing to her peers. By making the invites digital, her peer group can share them virally via email and text, being sure to cover the demographic that you're trying to attract.
Make it a Privilege
Students love to receive honors. If you're having a hard time drawing girls into your program, send out word to teachers. Ask the teachers for "nominations" of students that should be awarded entry into your program. You can take those nominations and balance your roster, based on the names that you've been given. Don't forget to save room to allow nominated students to bring a friend. Girls are more likely to stay involved if they have close friends by their side.
Create a Campaign
Perceptions of STEM begin to form waaaaaay before the invites for your program are printed. It can be a bit of a process to get girls to believe that your activity or event is "for them." See if you can hook up with a media teacher to get some volunteer time from two or three girls. Work with them to start a school-wide "Girls Can" campaign. Start creating posters, fliers, and digital images to plaster around their schools. Not only will this help with the reception of your program, it can help boost confidence altogether (just make sure that you don't put down boys, or indicate that girls are "better" than anyone else).
While these techniques are by no means guaranteed to bring in the girls, they will at very least spread awareness, and help to plant the idea into all students' minds that STEM is for girls, too!