It doesn’t matter what you say to open a girl. It doesn't have to be perfect. They’ll barely remember it. Make shit up on the spot or have a couple of forumla openers. One of mine that got lots of girls to talk to me, (since I moved to the area within the past year) was "Hey, I'm from Cali, what's a good place around here you enjoy? or I've done some dumb ones such as "Hey, I think you're cute".

Never directly ask “what’s your number” best to say “Let’s keep in touch. Hand the phone to her” something similar “I’d love to continue this conversation”. Honestly, my favorite is to never even ask a girl for her number. Let the girl hand her PHONE TO YOU. Honestly had this happen more and more often, and I simply don't bother asking anymore.

Hope that helps. God speed.