Friday, March 13, 2015

Charlie's Gumballs

My kids need more problem solving practice. Everyone knows being able to do the calculations is only a small part of math. The real math is seeing problems and determining the proper way to solve. A few days ago someone (I don't remember who, I'm sorry!) shared Charlie's Gumballs with me.

I loved it. It was just the kind of problem my kids need. Today to start math I switched on the video, told the kids we were watching a video and that's all, and played it. They were immediately on board and started doing the next step before I prompted them.
"Ok, what questions can we ask using this video?"
"How many did he start with?"
"How many did each person get?"
"Can I have some gum?"
I listed the (good) questions on the board and said, "Ok, that's your assignment. Go." Then I stopped talking, sat back, and watched the groups work.
I have to say I was impressed. There was a lot of gnashing of teeth and even more too quick too flip answers that they didn't double check, but once they figured out it wasn't as easy as they thought they got to work with an industry rarely seen with, "Do page 267, #2-24 even only."
There were math conversations happening, problem solving, team work, trouble shooting. I loved it.


  1. This is outstanding, Doug! I love seeing what students can do with problems like this. I've incorporated quite a few challenges from 101qs into my math classes this year and have been amazed by the results.

    How did the kids who weren't able to come up with a solution do with this? Did they show some understanding through the group discussions, or just back out and let others solve? Helping the students who give up too easily has been the hardest part of incorporating these challenges into my math instruction. I've had to require a recording sheet with student reflections to hold them accountable. Do you have any other ideas for that?

    1. The kids who weren't able to come up with a solution did a lot of, ummm, reverse engineering. They'd hear someone else talking about 120 and go backwards. That's fine, they were discovering strategies.
      I had to do a lot of prodding for the less persistent kids. We did it in groups, which seems to help because it's rare and entire group will give up, but they will all lean on one or two kids. So then I make the ones who tried to disengage explain the thinking.

  2. I've seen success with this with problems from Sean Connoly's Perfectly Perilous Math. I'll usually present the problem and have them try to solve it on their own. As they start making some progress, they will check in with others, compare thinking, have aha moments, realize the next step, and work together. Thanks for sharing this :)