I keep saying that games are a great way to build and reinforce math concepts, but even so, I am pleasantly surprised when I see it actually happening in action. I saw it happening again last week…not quite a year after I first introduced Yahtzee! to my younger son.

We brought Yahtzee! with us on our family vacation. The 6-year-old (Yes! He is a 6-year-old now) and I played every single morning. It was actually very pleasant…I’d make a pot of coffee for myself, bring him over a cup of orange juice, and we’d sprawl on the floor to play. As the week progressed, he became noticeably more strategic in his decisions, but even more so, he became noticeably quicker adding numbers together. He was even getting some serious practice with multiplication. I made sure to support this practice…here’s how you can, too.

He would roll something like this…

I’d watch him add the numbers together. Usually he would add the dice that were closest together until he had to resort to counting each dimple on the rest of the dice. I showed him how to group the dice differently to  make adding easier.

In this case, it makes sense to look for ways to make 10. For example, 1 and 4 is 5, and 5 and 5 is 10. Then 4 and 6 are also 10, and two 10’s make 20. I would phrase this to the kid in a variety of ways:

“10 plus 10 equals 20.”

“Two groups of 10 is 20.”

“Two times ten is twenty.”

And then we would move on. Don’t bother to ask “does that make sense?” because it doesn’t really matter in the context of the game. Your child will likely be motivated to notice these tricks because it makes the game quicker and the adding easier. Don’t spend too much time “teaching” because that will just turn the game into work. Trust that your child will pick up on these tips if she is ready to.

I was really excited (in a mathy way) when I noticed that the 6-year-old (and the 9-year-old when he woke up to join us) was getting some great multiplication practice. When he rolled multiples of 6 like this…

…I noticed he had memorized 6 plus 6 equals 12, but he needed to add dimples after that. So we grouped them again.

6 + 6 = 12 and the other 6 + 6 = 12, too. So what is 12 + 12? He consistently told me that 12 + 12 = 25. So I consistently told him that 12 + 12 is actually 24. I didn’t bother to prove it to him, because if he didn’t believe me, he could always count the dimples himself. And we needed to keep the game moving along. Over time he dropped his insistence that 12 + 12 = 25. Then I could start phrasing that dice combination in a variety of ways every time it, or something like it, came up:

“6 + 6 + 6 + 6 = 24.”

“Four sixes equals 24.”

“Let’s count by 6’s…6, 12, 18, 24.”

“Four times six is 24.”

The kid didn’t even know (or perhaps didn’t care) that he was getting at least a half-hour of math practice every day of vacation! Of course, since we have been home from our trip, the kid has shown no interest in Yahtzee! Time to get his attention with another game.

(Mathematically…this is real life math. This is all about using math facts, skills, and strategies to address an immediate need. The kid needs to figure out what his score is for each roll. He needs to understand whether he should roll again and what he is trying to roll. He needs to know the risks involved with these choices. These are immediate needs because he really wants to win the game. This is what makes the game so effective at reinforcing math skills and concepts. By the way…did you notice that grouping the dice in different ways to make it easier to total them reinforces the commutative property and previews order of operations? So cool.)