What is Multiplication Bingo?

We've been playing this for years. The "BINGO" board has a grid with multiplication products written in each square. One side of the board has more basic answers, while the other side is more advanced. On Poker chips I wrote multiplication problems - difficult ones on one side of each chip, easy ones on the other. 

How we play: I choose a Poker chip at random, and call out both the multiplication problem on the front and the back. The girls have to quickly figure out the answer, find it on their boards, and mark the spot with a coin from our travels. Whoever gets a straight line first, wins. But we always end up playing at least 3 gams because the kids scream for more. They love it! 

By the end of a game, the boards are sparkling with unusual, beautiful coins from all over the world (which often sparks discussions). It's great fun.