Thinking Tasks

Over the next several days, I’ll be sharing insights I gained as I worked with a group of fifth graders to test drive the first three practices from Peter Liljedahl’s Building Thinking Classrooms (BTC):

• thinking tasks
• random groups
• vertical, non-permanent surfaces (in our case, white boards from Wipe Board)

For today, let’s break down the task:

I gave students the “Missing Cards” task from Mashup Math’s 10 Free Math Riddles for Adults. It states: “A few playing cards are missing from a standard 52-card deck.” It then outlines several conditions that are true when the cards that are remaining are dealt to three, four, and five people.

This just so happened to be the same riddle I gave to our teachers back in March as we launched into the three BTC practices. Within minutes, these fifth graders starting working the problem in the same way their teachers had.

The difference: This time I knew what I was looking for.

I watched as all seven groups started dividing 52 by three, four, and five people. I watched to see if any group might realize their mistake. When they didn’t, I waited some more, until I heard a group reviewing the constraints of the problem. I seized the moment to pull them all back together.

I said, “You all are starting with 52.” I paused and then said, “That’s a full deck.”

Someone shouted out, “But there are cards missing!”

They didn’t need an invitation from me to get back to work. Groups changed their starting number and I shifted my focus to helping to name (and nudge) the strategies they were using to solve the problem.

The best part—even better than having to ask their teacher if I could have a little more time—came in the debrief when I asked them “Why might we have chosen a task like this?” Check out what they said:

Simply brilliant!

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Stay tuned in the coming days as I share more about the problem-solving strategies students used as well as the other two practices that make up the first BTC “Toolkit”: random groups and vertical non-permanent surfaces.