This is the behavior chart I use for my after school students. Our program is three days a week for 2 and 1/2 hours a day of homework and then reading and math, so if they make it through well, they deserve a treat! Each student has 6 letters of their own name, and can lose letters for not coming prepared (pencil, hw, etc) talking, disrespect, not doing work, lack of focus, etc. I allow them to lose 2 letters a day out of the total of 18 for the three days meaning they must have 12/18 letters remaining on Thursday afternoon in order to choose our of the prize box which has essentials (dry erase markers, highlighters, glue sticks, pencils, sharpeners, erasers, etc) as well as fun stuff (depends on what your kids are into- mine love sunglasses, glow sticks, bracelets, stickers, colored blow balloons the ones that smell awful, lip gloss, finger lights etc) which I purchase weekly from the dollar tree/dollar general and I encourage them to make smart choice before a fun choice. I tell students when I am taking a letter, but if you kids are younger or more visual then make a name chart on butcher paper as well and use colored page tabs to cover up their letters when they lose them so they can see how many they have lost, but keep track on the paper as well. My kids really work hard all week and strive to have no letter taken so they can pick two items instead of one, and sometimes three items if they are one of the few who did not lose any letters all week, it works wonders!