Which One Doesn't Belong?: A Shapes Book

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What is the average class size at this school?” would produce numerical data with some variability. This bold-color shapes book is, as the author had hoped, “a resource that can make a meaningful contribution to geometry instruction” (p. 16) but can also reside in an elementary school library. It allows for meaningful conversations, unanswered questions, and deep dives into the subtle and complex similarities and differences between shapes. For each of the 4 questions, write a survey question that will help you collect data from the class that can be analyzed to answer the question.

At the conclusion of the unit, I would like to repeat the activity and see how their answers and explanations change. Will I see any growth in their vocabulary? Will they notice new differences based on the properties of the figures?

Number 2

I plan to continue exploring this book and use it again next year, but with a few changes. I think it would be very beneficial to do this activity first, as a pre-assessment to our geometry unit. What do they already know? What misconceptions do they have? In the bottom right corner: 4 triangles are joined at the points form a big purple and green square.

So what about this one? What's one reason why this one doesn't belong? OK. Yes, it's... Oh, I almost said it's the only domino with three on it, but it's not actually. A speech bubble out of the yellow shape appears that reads: This one shows a near double… double 2 and 1 more is 5.] Speaker

But there was so much I didn't know! This teacher guide--which is not so long but long enough to have depth and lots of new learning--helped me to understand how much more powerful this routine could be if I were more intentional as a teacher. The focus on geometry is interesting to me because it is an area of math teaching that I need to learn more about. The book has an entire chapter called "How Children Become Geometers". This chapter helped me see the big jump kids do from elementary school to high school geometry and how much better we can do to help them build understanding by understanding the levels of understanding kids have and build around geometry. Give students 2 minutes to write a question of their own that could be answered using data from the class. After giving students time to discuss the questions in their groups, pause for a whole group discussion. I started sharing WODB activities with my students because I was struggling to find ways to get all of my students engaged, especially those who struggle with mathematics and are reluctant to participate. In the bottom left corner: 4 triangles are joined alternating on their angled sides to form a parallelogram.] Speaker The NSW Department of Education is committed to employing the best and brightest teachers who can teach and make a difference in NSW public schools.

What's the reason why this domino doesn't belong? Ah, yes, I had noticed the same thing that some of you noticed… Makes sense, doesn’t it? But, is it mathematically correct? I don’t know. My students gave me some pretty good arguments justifying their reasoning! We decided we needed to do some research on the word scalene. Does it only apply to triangles?

With your group, decide what the responses for question number 1 have in common. Then do the same for questions numbered 2 and 3. How many students are on the roster for this class?” would produce numerical data that does not vary. There is only one value in the data set, so there is no variability. A speech bubble out of the yellow shape appears that reads: Oh… this one is a near double too… double 5 is 10, then 1 more is 11.]

Another observation I found very interesting was how students borrowed vocabulary from one setting and tried to apply (maybe misapply) it to a new setting. Have you ever heard of a scalene quadrilateral? Neither had I! And this one? Has three, mm-hmm. So if you had to make an argument or case for why each domino doesn't belong, who would you argue for does not belong? In the top right corner: a purple triangle and a green triangle create a square, is next to a purple triangle. Below the purple triangle is a green triangle. Under the starburst, a blue text box appears with text: Can you make a case for why each one doesn’t belong?] SpeakerI love the answer key in this book. The thing about this WODB sets is that they are designed so every answer could be the correct answer. So the answer key shares insights kids may notice about each shape and how they might respond. It is a great resource and a great place to understand how to create your own sets (and help kids create their own.) Even though the book says “every answer can be correct,” my students had a hard time believing that two, three, or four different answers could all be correct. We decided to find out! A speech bubble out of the yellow shape appears that reads: It’s the only one that shows zero and some more.] A yellow round shape appears over the 4:4 domino in the top left section. Then the shape moves across to the 6:5 domino in the top right, then over the 2:3 domino below, and then across to the 3:0 on the left.] I think it would also be very interesting to have the students write their own reflections. Did they find this activity interesting and why? What do they think they learned from this activity?