Okay, I'm in my French class (minutes before it starts) and the room we're in consists of desks for two and two people. I have about 4 good friends in this class so somebody had to sit alone, that was me.

Then three girls enter the rom (a HB7, a HB6, and a HB8) The HB8 seats herself on a desk beside the two other girls.
This is how we're seated:
Me:O
Her:X
Empty space: o
xx oX xx xx
xx oX xx xx

About half way trough the class the teacher says we are going to work two and two togheter to improve our speaking skills. He looks over at me and the HB8 and says I should work with her. We start asking eachother random questions. Then the teacher says everyone should try saying thier phonenumbers to one and other (we where also told to write them down so we could check that it was right, we didn't need to say our actual phonenumbers)

So I start with by saying mine to her and she begins writing it down (I said my actual #. She got mine right) When its her turn, she struggle a little to get it right. When she looks at what i noted she says it's correct. After that we just sit and talk about random stuff until the class ends (not in French)

Now, what should I do with the number? I don't know if she gave it to me because she had to or because she wanted me to know it.

Mode

yeah bro, I think this was because she had to. Use an opener like a remark about her handwriting (did a cave man draw this ?<smile>) Or you can catch her staring at you one day (What is this look im getting? <sheepish smile>)
then run game on her like you would any girl. When you get to the point of exchanging numbers, make her fig it out in French.