popa_bar_abba
Would you tell your daughter to give her phone #?!
I would tell my daughter to do whatever she wanted.
I was responding to the OP who asked what she should do, not what is appropriate.
So, if she was interested, then there is no reason not to give her phone number. Of course, some girls will be turned off by a guy who hits on girls in school.
If she was offended, by which I mean like all the posters here, then she should tell him his comment is inappropriate for a professional relationship. Which it is.