I use these Brain Bucks as an incentive for reading at home but they could be used as a reward for any behavior you want to increase the frequency of. I copy the Brain Bucks on different colors of paper to represent different values (e.g. green =1, blue=2, gold=5) and students can trade in the colors once they have the specific amount (math skills are also being reinforced ;). Finally, on the predetermined day, students can shop for prizes or priviledges. These Brain Bucks serve as a tangible motivation for desired behavior.