Lots of good math center games for the young ones. Yahtzee - "This game is so funny to see how excited the kids get. All they have to do is roll 2 dice and cross out the sum. They keep going until they have crossed out all of the numbers.
These are printable magnet pages. You can find these at Making Learning Fun. She got colored puff balls and glued little magnet pieces on the back. These you can use on a small cookie sheet or a magnet board. More activity bag ideas on this post!