Let’s play cards! 

By Mike O’Hern, Center Director of Mathnasium of West Knoxville

When I was growing up in the dark ages the holidays would mean a lot of traditions. Thanksgiving weekend was spent with my cousins playing board games that would inevitably end up in accusations of cheating from all sides. (I’m fairly certain that this was because there was cheating from all sides.) Christmas would mean drives in the car to look at the wonderland created by virtually every house lit up with Christmas lights. We would do puzzles and play more board games, but my very favorite tradition was playing cards.

Now I know I’m going to sound like an old fuddy-duddy, but I have been disappointed to see that most kids we see in our learning center don’t know how to shuffle cards. Playing cards stealthily builds math skills: counting, adding, comparing, categorizing, probability (“the odds” or the likelihood of something happening), and even strategy. But even before your young learner is likely to be able to join in a game of bridge, that same deck of cards can be a fun way to become fluent with math facts. For your holiday fun, here are some ideas.

First remove the royalty (jacks, queens, and kings) and call the aces “1.” Now you have a deck of numbers, one through ten, with four of each.

Make it ten. Lay one card face up and ask how much more to make ten. You lay a seven, so you say, “Seven and how much more makes ten?” When your student starts getting it down pretty well she’ll enjoy going for speed.

What’s the difference? Lay out two cards and ask how far it is from the lower number up to the higher one. You lay a seven and a three, so ask, “three and how much more makes seven?” You can then say that this is just another way to think about subtraction: Seven minus three is the same answer! Want to make this a little more challenging and have your student learn a new concept? How about asking, “Where do you end up if you count down seven from three?” Negative four! Terrific! So three minus seven is negative four.

“…even before your young learner is likely to be able to join in a game of bridge, that same deck of cards can be a fun way to become fluent with math facts.”

(While we’re on the subject of negatives, a good way to introduce the idea is with a swimming pool. If you jump from five feet above the water and altogether you go down eight feet, how deep are you under water?)

Keeping up! Lay the cards out, one at a time, each one on top of the last. Your child will keep a running total by adding the black cards and subtracting the red ones. (If you don’t want to get into negative numbers, make sure the first few cards are black!) You lay a black seven then a black eight. 15. You now lay a black four. 19. Now a red five. 14.

What about games for two or more players?

Ten-buddy concentration. Lay all the cards out face down. In turn, each player will turn over two cards. If they add up to ten, they keep the cards and play again. If not, they turn them back over and the next player gets a turn.

What’s my number? Each of two players gets half of the cards stacked face down in front of them. The third player (or you if there are only two kids) will be the “referee.” Each takes the top card and holds it face out against their forehead. The referee tells what the sum (or product, if you prefer) and the first to say what the card on their forehead is wins those two cards. They can either play through the deck once and count who has the most cards to finish the game, or they can recycle the cards and play until one player has them all.

So why not have some fun over the holidays? The math will come pretty quickly, but the memories will be about having fun and playing together!

Mike O’Hern, Center Director of Mathnasium of West Knoxville, earned his Bachelor’s Degree in Metallurgical Engineering at the University of Tennessee, Knoxville in 1988. He pursued graduate studies in Materials Science & Engineering while on the Research Staff at Oak Ridge National Laboratory. Mike has had a life-long love of mathematics and teaching, and feels that math is not about learning to be ready for the next math class – it’s about learning to think.