I use numbers because: text books, math kits, notebooks etc so much easier for me to put in number order than alphabet.

I do not have to redo ideas each year

Mailboxes, supplies etc are same for each year

Less obvious to put up number than a childs name for recess issues/washroom. homework not done etc

Plus most teachers know that if you ask child to write name on the board it can be painstaking long process.

They use numbers to book in to centers for math /language arts

New students just get the last number

I put class set of numbers to draw for special activities, how many times do you need to choose who will present first, etc. I draw a number (problem solved, not favorites)