In the file, you will find 5 gift certificates that can be issued to students for excellent work. These certificate are redeemable for 100% on a home work, class work, or quiz, but you can modify them however you like. You can print them out on card stock paper, put the school crest on it, or stamp it with a personalized stamp.
I would issue them to students who performed additional mathematics research when I asked topics in class. I will also post some questions that I would ask students. In my class, it motivated all of my students to complete outside research.