Should you give a girl your phone number on a note?

I think its cool if you between 13-16. But beyond that, i think a more sophisticated approach is more acceptable.The way I see it is a 50/50 chance. Also you'll never know if you dont ask.Just use the "hey you got anything planned (for whichever day you choose) and say, "if you'd like to hang?"If she's busy jus say, "well maybe you can let me know when its a good time for you?"