I ask all my parents to donate a bottle at the beginning of the summer (usually May 1st) then I use these one at a time until all bottles are fininshed (this way I am not opening, closing, switching and bringing with me five bottles) I do put it on all the children face and just be extra careful around their eyes.
I also ask that parents bring them to daycare already sunscreened in the morning so I only have to do the afternoon lather up :-)