Asking for her number tomorrow

I’m asking for her number tomorrow and I’m so nervous omg. we sit together in 5th hour and we’ve been taking (her complimenting my art project and stuff) recently and her friends have been coming over to play four square with my friends and she comes along too and watches. she’s my first ever crush and I’m super nervous, but I feel like I need her number before summer break or else I won’t be able to talk to her at all. im so shy around her, and have no idea how I’m gonna do it. wish me luck guys