If you haven’t heard the latest meme going around, it’s a video of a kid saying 9+10 is 21 I won’t go on about the video, but in my class at the moment the kids think it’s funny to respond with “21” to just about any question.
Anyway, on Friday we took our first field trip of the year to climb Mt. Monadnock (above). It was a beautiful day, and everyone had a great time. Now, there’s nothing like getting to experience a group of 8th grade boys chatting on a two hour Friday afternoon bus ride.
See if you can figure out the pattern:
“What’s 9+10? 21!”
“What’s 22+22? 46!”
“What’s 15+20? 37!”
Then we pushed our knowledge a bit:
“What’s 15/5? 5!”
“What’s 5×5? 27!”
I was hoping to get a light to turn on that inverse operations didn’t work in our number system, but had no such luck, and didn’t feel much like pushing them on a bus ride back from a field trip.
Then a student asked me if I would still give him credit if he started writing his answers in class this way. I told him I would, if he was consistent 100% of the time. Then I challenged him to see how well he understood his new number system:
This one took a minute, then several kids shouted out “17!”
“But 3+5 is 10, and 10+7 is 19. shouldn’t 3+5+7=19?”
This created some excellent discussion.
I’m skeptical that any meaningful math learning happened during our conversation, but I’m happy that we were able to laugh and joke about math outside of school. I hope my students appreciated that as well.