These kids are asking for permission. They are using MAY I...?, which is more polite than CAN I...? Notice also how the teacher gives or refuses permission.
Mr Brown, I don't have scissors, may I use yours?
Sure, go ahead
Thanks
You're welcome
Mr Brown, may I go to the bathroom?
Sorry, you can't. Finish your work first.
Please!
Ok, go ahead.
A comedy movie fragment: May I go to the bathroom?
- Excuse me, may I go to the bathroom first?
- Of course you may.
- Thank you