My third graders love this once we have covered all multiplication facts. On a name tag I write a multiplication problem (ie. 7x5) Each students gets to wear one for the day. They no longer have a name, but now a number. When a student wants to speak to someone, they must call them by their answer (ie. I'm Mrs. 35) This is a great way to keep them up on their facts and other students and teachers in the school enjoy calling my students by their number.