This file includes 20 cards with 1-20 hearts on each card. Children count the hearts and use a clothespin to clip the correct number. Perfect for a Valentine's Day center. To make this a self checking center activity make a dot or place a sticker on the backside of the correct answer. The clothespin should cover the dot or sticker when it is clipped to the correct number. Children can then turn it over to check if they counted the correct number.