To do this, you assign a secret number to each child. I gave mine a label with a number on it that they keep in their binders in case they forget. I just numbered the seats in order around the room, so I would know each number myself. When a question is posed, each student gets a post it and puts their number in the corner before writing their answer. Then they come and stick it on the board. I can easily determine who has it and who doesn't. In the future I will make a grid board with the spaces already labeled by numbers so that students can learn to put their post it in a designated spot, rather than remember their number.
I used this activity with our math program and we discussed each one of the incorrect answers on the post its. It was a very good lesson even for those that already understood, because they could explain why other answers were incorrect.

