I'm wondering if anyone could tell me how to write some very short recess scene at a school? I'm out of ideas. P.S. this would be acted.
The best general-purpose answer would be for you to just go observe recess at a local school of the right age group from the correct side of the fence. But if that's not really do-able:
Usually there are several different groups of students playing at specific things. Depends on age of students currently in recess. Taking a couple of 4th-grade elementary classes at recess as an example:
five students are playing "lava monster," which involves trying to move from one part of the play structures to any other without touching the ground (with more than one foot briefly). One student is the lava monster, s/he stays on the ground and tries to drag the other students onto the ground: if they touch it with both feet, they become lava monsters. Sometimes the original monster is then a free student again, sometimes the lava monsters multiply until only one student is left. Regional variations exist.
Three students (or four, depends on equipment) are swinging on the swings. There may be one or two waiting their turn, but usually, they find something else to do until the swing opens up.
Two students are going down the slide in turns. This group changes members frequently.
Two girls are off to one side whispering to one another and/or giggling.
Several students are in one of the grassy areas playing some kind of large-ball game. Usually, this is not an organized activity so it's not likely to be anything like what you see in gym class.
One kid is at the top of the climbing structure just hanging out, possibly occasionally turning upside-down.
One kid is inside the "climbing tube" that connects one part of the play structure to another. This may potentially cause conflict with some of the lava monster players.
Two kids are taking turns doing silly stuff on the low beam/railroad tie/kerb along one side of the playground - walking it backwards, standing on one leg until balance is lost, duckwalking without falling off, etc. This may occasionally interfere with a lava monster player.
If there are two playground monitors, they are very likely to be talking to each other, at least until somebody falls or yells at the injustice of somebody else.
One kid is building stuff (sculpting?) in the sandbox, even though most of the kids wouldn't go near the sandbox as it's seen as a "little kids" thing. Maybe s/he's a slow kid, maybe s/he's an artistic genius, maybe both. In any location that is not totally enclosed, sandboxes are a health hazard (local feral cats love to use them) and have been removed, as were the teeter totters (concussion hazard). As long as all of your background characters know what they are supposed to be doing and for how long, your foreground action/dialogue can run with a convincing background. Remember there is often shrieking, so either allow for it or record on separate tracks and "dreamlike" lower it in the final mix.
But I strongly recommend actually observing, it's fun and gives you much more acute observations.