A folder for elementary or high school? That's a lot of lugging around - on and off the bus twice a day, plus whatever he's carrying with him in a backpack.
I'm assuming he's not lugging it around to each class so he'll be locking it up outside. That makes it a target for theft. If he does this, recommend that he remove the front wheel and take it to class with him (or put the front wheel in his locker if it fits) so that the lock can't be broken and the bike ridden away.
The only way a folder makes more sense here than a non-folder is the ride to and from the bus stop, and it's a lot of lugging around just for that. I think it's probably easier to explore a used mountain or road bike and have him do the entire trip that way without the bus. My school was a few miles away and I would ride pretty much all year - even in the dead of winter - but not everyone wants to do that.