One of my opening week activities is to have each of my students create and decorate a circle with their student number on it. I laminate it and hot glue it to a magnetized orange juice lid. I use the lids on the front chalkboard for activities like voting, who's up for current events and who gets the couch during D.E.A.R time. My students' numbers are assigned alphabetically in the beginning of the year. My number is zero because everyone knows it all begins with zero!