Why are warm ups important to write in school?

If you're asking about when you walk into the classroom, and there might be a warm-up on the board that your teacher might want you to complete. It's something for you to do, to get you ready for class, and so you're not sitting around making loud noises with your peers. In my 6th bell, my teacher is on hallway duty. He'll be standing on the other side of the hall, and leaves a warm up for his to do while he's out of the classroom. It's basically just getting you ready for class. Hope this was helpful!!!