Talking Math With Your Parents

I spent Thanksgiving break at my parents house. This involves a lot of time spent playing games. The conversations during the games Saturday evening stuck out to me the most. Now, my brother is in medical school and I'm a math teacher, so when my parents talk math with us it isn't to teach us reasoning, but because it is so engrained in all of us that these are the conversations we have while playing games, no matter how old we are.

Cosmic Wimpout: 

My mom rolls 3 fours and a ten. She is way behind. Should she roll the one remaining die and keep all four scoring dice or only keep the ten and hope for better scoring dice? We discussed some contributing factors (if she only rolls one die she will need to get a five or ten out of the six options, that's a 1/3 chance, if she rolls all four there are lots of good options but also lots of bad ones) but didn't solve the probability problem. It's still on my mind though and I'm tempted to solve it now.

Dealing Cards: 

As I deal the cards, my dad counts aloud the number of cards he has. 1...2...3...4...5...6... ... He doesn't count the seventh card. He leaves us hanging. Finally someone breaks and says seven! This repeats a few rounds, then he doesn't count at all during the following deal. My mom and I take turns counting (she says the odds and I say the evens) without announcing that's the plan. 

Tallying Points: 

At the end of a round of 500 Rummy you compute your score. Any cards you have on the table are positive points, any cards still in your hand are negative points. My mom was recording other people's scores so my dad started helping her tally the number of points she had on the table, he got 48. However, she wanted to use a strategy of making zeros - match a negative six in her hand with a positive six on the table. Since he had already added up the positives, my mom decided to be flexible and go with his method. She found two cards in her hand that made ten, put them down and said "ten." My dad responded "38." Which got strange looks from the rest of us until I realized he was finding the total. My mom made another ten, my dad did more subtracting and eventually we found her score. At the end my mom and I shared that first, we make zeroes. If that's not an option, we add all the positives, then add all the negatives, and finally subtract. We laughed and decided my dad was weird, although his method was also valid. 

Discard Pile:

We play the all or nothing rule. If you want some cards in the discard pile you can have the top card or the whole stack. The pile was getting more and more tempting so finally my mom picked up the whole thing. She only put down 30 points so I asked if it was worth it. She thought she only added 28 points to her hand so it was, barely. But she created lots of future opportunities. I went out the very next turn. I turned to her and asked again, was it worth it? She said maybe not. I offered, what if you'd had one more turn? And she responded it probably would have been worth it then. 

Negative Scores:

One round my dad lost seven points, his score the previous round had been 403. My mom, as scorekeeper, said "I have to go back into the 300's!" I commented that this is difficult because you have to think about all three digits at once. 

This post was inspired by Talking Math With Your Kids (the blog and book). Christopher Danielson, how did we do?