How do I work up the nerve to ask this girl for her number?

oh don't worry about popularity and stuff! girls don't do that kinda stuff that she does for nothin. so this is what this guy that i liked did to get my number: we were just talking, having a normal conversation and suddenly he pulls out his phone and shows me his wallpaper and then he's like, "hmm... i don't think i have your number. can i have it?" and i gave it to him. and another one of my guy friends took my phone for a minute and used my phone to text himself so he had my number then started texting me. it was kinda weird but it might work for you. or you could just straight up ask her, "hey, can i have your number?" if you're feeling bold. also when you get her number text her the day after. hope this helped!!!