When should i ask for her #?

[skinnyanimal125]

Me and this girl have been talking a little after class. We arent too close yet because the only time we have to talk is in between classes. And I want to get to know her better, so should I wait longer till I ask for her number or it doesnt matter? And how should I ask for her ? In the middle of the convo or when its over? And is it wrong if I ask for her # over facebook

[Sarah]

As a girl I would suggest you ask it face to face and not fb. Also in the middle of the conversation its ok. Theres no reason to wait longer. You can ask now if you want to know more about her also the most important you can see if she's interested from her reaction when you ask the #