I may have hit upon a way to deal with the "I have to go to the bathroom" requests that have a tendency to spread like wildfire after the first kid asks to go.
I had 29 third graders today, and in the time between the start of school and first recess, I have no clue how many kids had to go. I don't like to decline the requests, because, well, they may have to actually go.
So, when I went out to get them from recess, naturally a few asked to go before we went in because they "forgot." I lined them up in the hallway outside the classroom, made them all sit down and listen (not the easiest feat) and numbered them off. I told them that they would get to go when and only when their number was called. There would be no extra trips and no extra drinks of water before lunch.
Then we went inside and sat down and did our work. I called them group by group at at time. All the 1's, then the 2's, etc. Shockingly, it worked. Only one kid missed his number being called and asked me later if I ever called it. Nobody whined or asked to go a second time.
I may make this a standard practice. It beats sending them all at once at that age. The problem was, I numbered off to seven, which meant I had four kids out at a time. That may be too many. Next time I'll do the math better and only have two or three. As always with subbing, something that works once can be a fluke. There's no guarantee it'll work again, but I may try it tomorrow when I'm in with fourth graders.