How to make sure substitute teachers can find your sub plans
If you know you’re going to be absent, leave your sub plans in a conspicuous place–and write the location of the plans on the whiteboard.
Spell it out–“Sub plans are on my desk.” (Or the back table, or the podium, or the computer table–it’s surprising how many potential places there are to leave sub plans.)
If your absence was unplanned–perhaps because you woke up sick at 6:00 am–then you could email your plans to colleagues and ask them to place them in the room ASAP. Ask the colleague to either speak with the sub or write the location of the sub plans on the board.