Every twenty seconds they change the numbers they say they've called completely. So pay no attention to the little guys holding numbers. What we do, is check off all the numbers on both our cards. Then, each time the screen refreshes, we look fast to see if a full card of our numbers is shown on the callers card. If you see all the numbers, call bingo fast! If you don't do it before they refresh, they will say you are wrong. Also, always call bingo at the end of the game, just in case!