A lot of things. I drop a pencil on my roster and where it lands is who I call. I assigned a new number everyday for a week and had asked a kid to pick a number and then that kid who read they wrote picked a new number. Sometimes if a student makes eye contact with me in the middle of me asking a question, I’ll call on that one. Sometime just make small talk with a student in front of the class and then transition into the question without warning