These are very helpful when it comes to a behaviour strategy. I worked these out myself and they are really helpful as I make use of these as motivational positive reinforcement.
I work like this: Students are rewarded tickets (see my other product for tickets), and when they get 5 tickets they can exchange them with one token (in this product) and as soon as they get 4, 5, 6, 7, 8 etc. tokens they can exchange them for a rewards such as stationery etc.
Each student will be assigned a number and this number will correspond to the number on the tokens/tickets