Alternatively, for questions with small answers, have every student write their answer on a small whiteboard and hold it up. Doing so (a) allows the teacher to see at a glance who does and doesn't have the answer, (b) doesn't shame any student with the incorrect answer, and (c) requires even more student engagement (if your pop-sickle stick was pulled first, you could still zone out while the rest of the class' sticks are pulled.)
