Numbers are shit. Go for the pull. I sometimes get numbers and I guess in social circles its different but in cold approach go for the pull. The number is a complete after thought. Cooooomplete after thought. Like this ''well give me your number/take my number' if for whatever reason you cant take her home. Im not saying numbers wont be fruitful BUT they shouldnt be the aim of your interaction. Even if numbers are all you care about, treat them like its a plan B.