I made a certificate a while ago if you want to print it out: I haven't actually tried printing it out, though, so if the yellow doesn't show up, let me know and I can change it. (You can also view the image directly on imgur here: http://imgur.com/sAErSgu)

Wooooooooooooooooow

I reward my students with free time, but I also may hand out one small piece of candy. My students love Wirther's, you can buy a large bag for a relatively low price at stores such as CVS.

nice job!