Woodjie has a little drawer full of coloured plastic animals, flash cards, his Game Boy, and a Boggle timer. As you can see, his worksheet is a laminated picture of him with five velcro buttons. There are real buttons with sticky velcro on them we use as tokens. When the board is full, Woodjie gets to play with his Game Boy until the timer runs out.
I have flash cards from school that I laminated (smiley face = "happy," or we have "heart" and other common words). I show some of these to him and after I feel he's done enough to earn a token, I give him a button. There really are no rules as to how many he must answer correctly. Sometimes I give out buttons when I see he was frustrated but did a good job on a card. Other times he's zooooming through his cards and perhaps I give him a button when he finally pauses for breath!
The girl is usually nearby doing her own activity (today it was stringing plastic beads). Woodjie is very proud of his work and is showing his sister his game on the Game Boy in the last picture.