# Domino bingo

By **Susan Milner**

Everyone seems to like bingo! Here are some variations that use dominoes. The game itself is appealing, gives students practice with addition and subtraction, and can form a good introduction to probability.

The grids come in three sizes, using 9, 16, and 25 dominoes respectively. They are designed for 1"x2" dominoes. You can make your own from the given template using construction paper or plastic foam.

I’ve played this with students as young as grade 2. That group started with the 9-domino version and progressed quickly to the bigger playing grids. We started with addition, then tried subtraction, then went on to a game using both.

I use plastic foam for the counters for the bingo caller, one colour of counters for addition and a different colour for subtraction. The frequency of the result differs with the operation, and we want each domino to have the same chance of being chosen. For example, there is only one way to get 0 via addition (0+0) but seven ways via subtraction (6-6, 5-5, etc), so we need to have more 0 counters when using subtraction. Trying to figure out the number of ways to get each sum or difference is an interesting exercise for any age . I’ve provided frequency charts in case you don’t have time to do it before you play bingo.

### Addition

Players choose enough dominoes to fill in the chosen grid. The caller chooses a number and everyone hunts for a domino on their grid that has that sum. If they have such a domino, they remove it from the grid. Only one domino may be removed per call! You decide what constitutes a win: a single blank row, column or diagonal; two of them; or a completely clear grid.

### Subtraction

Same idea, only this time players hunt for a domino with the called number as its difference. Students sometimes ask if order matters, so this is a good time to discuss what “difference” means. The difference between 2 and 5 is 3, no matter what the relative positions of the 2 and 5 are.

### Both

Once the players get the idea and have practiced a bit, try combining the two sets of counters in one bag.