I drew a poster with a cartoon of an empty chair entitled, 'Secret Chair'. Sometimes before class starts, I randomly select a chair and place a sticker underneath it. When the students enter and see the Secret Chair poster in its designated place, they know to check their chairs. Whoever has the sticker gets to go to the treasure box and select a prize. If the student who has the sticker is absent he/she does not get a prize and the others tell the student the next day. Thanks to the 'Secret Chair' attendance has been great!