I finished twenty minutes early.
The work is done, the room knows it, and there are twenty minutes left. This is where a period that went fine can still come apart.
Don’t announce free time. Say what’s happening next before the room decides for itself: “We’ve got fifteen minutes — here’s what we’re doing.” Any structure works. No structure doesn’t.
Why this happens
The end of a period is the hardest part to hold and the part nobody plans for. You’ve spent forty minutes building enough credibility to run this room, and unstructured time spends all of it at once — because the moment there’s nothing to do, thirty people go looking for something, and what they find won’t be what you’d have picked. This isn’t really about filling time. It’s about not handing back the authority you just built.
What to do
- Decide before you announce. The gap between “we’re done” and “here’s what’s next” is where you lose it.
- Keep them in their seats for the first minute. Movement is the hardest thing to undo.
- Run something with a shape — a question with an answer, a quick round, a challenge with an end. Open-ended time isn’t structure.
- If you let them talk, say so explicitly and put a boundary on it. “Five minutes, at your desks, then we clean up.”
- Use the last five minutes for cleanup and a closing question. Ending on a task rather than on a bell is the difference between handing back a room and abandoning one.
Say this
K–2
Twenty minutes is a long time at this age, and a story or a movement activity is the honest answer. “We’re going to do something together, then we’ll clean up.” Don’t leave them to fill it themselves.
3–8
“We have fifteen minutes. I’ll take three questions about anything, then we’re doing this.” Giving the off-topic thing a defined slot stops it taking the whole twenty.
9–12
“You’ve got the rest of the period. Quiet work, phones as your teacher allows, and we’re still cleaning up at five till.” Naming the terms and the end time is the whole move.
Where the line is
- Yours: what fills the time, and whether they’re in their seats.
- The office’s: leaving the room, going outside, anything that moves the class.
- The teacher’s: whether a video, phones, or free time is fine in this room. If you don’t know, don’t.
If that doesn’t work
If it comes apart anyway, go back to a task with a clear end — cleanup, collecting work, even attendance again. And write down that the plans ran short. That’s useful information for the teacher and it isn’t a complaint.
In the note
The packet ran about twenty minutes short, so we filled it with a discussion round. Might be worth a little extra next time.
From Holding the room in The Sub’s Handbook.
Written by a substitute teacher, for substitute teachers. This is what’s worked in real classrooms — not official guidance, and not a substitute for your school’s policies or your district’s training. When something feels beyond you, it probably is: call the office. They’d rather hear from you early than late.
Open subin, the app the handbook comes from. Free to use.
Dan McSpirit is an active guest teacher and the author of The Sub’s Handbook. He built subin for the job he was doing at the time. More of his work is at danmcspirit.com.