Talking Points – 2D Geometry

We are about to start out work with Polygons, so I decided to kick it off with Talking Points. If you have never read about them before you can check out my post or Elizabeth’s post to learn more.

Here were the points my students were discussing:

tpgI had gotten these points by looking back at their fourth grade geometry unit work and thinking about what misconceptions or partial understandings students have each year when we start this unit.

This time, I made a few changes from past experience. In each group I had a facilitator to be sure that everyone got a chance to speak without interruption during Round 1, and a recorder to keep the tally for the group. Also, after the first talking point, I had advise from a math coach in the room filming with me to add individual think time after the reading of the point. LOVED IT! During think time, they were jotting in the journal and getting their thoughts together. I got things like this from just the think time:

IMG_8057 IMG_8059 IMG_8062 IMG_8069 IMG_8070

It was nice to see them take ownership with their journal without being told to write anything down. They were working on proofs before they started. After the six talking points, I posed three questions on the board for them to reflect upon individually:

1 – What talking point are you sure you were right in your answer? Explain your reasoning.

2 – Which talking point are you unsure about your answer? Why?

3 – Which talking point did your group agree upon easily? Why do you think it was easy for your group to agree on that one?

Here are their reflections:

IMG_8039 IMG_8041 IMG_8043 IMG_8046 IMG_8048 IMG_8049 IMG_8053  IMG_8055IMG_8054 IMG_8060 IMG_8061 IMG_8066 IMG_8068

Never anticipated so much “left angle” talk in my life 🙂 I learned SO MUCH about their understandings and wish I had time right now to add my comments to each journal, but I will very soon!

So, I have a moment here at lunch to reflect on what I learned from these talking points:

TP1 – As I anticipated, this one is always a source of confusion. Every year it seems as if the students know the sentence goes one way or the other but can’t remember it because there is little understanding of the WHY piece. Later on in the unit after we have done more classifications, I do more of these statements with Always, Sometimes, Never, so this is a something I wanted to see how students were thinking about it. Most tables said something to the effect of “I remember last year we said a square is a rectangle or a rectangle is a square, but I can’t remember which one.” Another conversation I heard was that a rectangle has to have two short sides and two long sides.

TP2: I loved this question and was really pleasantly surprised to see some trying to draw it and ending up with unconnected sides. One thing I was so surprised about was the “left angle.” They were not thinking the degrees changed so much from the left to the right angle, but more the orientation of the angle (left side, right side). Interesting.

TP3: I got a great sense that most students knew what area and perimeter were and the best part was that if they didn’t remember, someone at their table did and gave an example. Regardless if they knew they could be the same, I was excited to see a great understanding from most here.

TP4: This one was great. I saw some students drawing a square on their paper, showing the group, rotating the paper and saying, “See, now it is a rhombus.” They all seemed to be in the mindset that a rhombus is a diamond shape, but really not reasoning about the attributes that make it a rhombus.

TP5: They did a very nice job with this one. A lot drew examples of combining two shapes, while I heard others asking their group if the “inside connected side counted” when they were trying to name it.  Also realized that the term polygon was not familiar to most students. I am wondering what they called them in earlier grades? Pattern Blocks? Shapes?

TP6: Interesting one here and it is where we start our 5th grade work with polygons, classifying triangles. Again, the left angle reappeared:) I did hear a few struggling with the name of the angles, obtuse, acute, right but then I had some that said there are other 3-sided shapes that aren’t called triangles. Hmmm, can’t wait to find out what they are! Of course, you always have your comedians who say agree because it could be Bob or Fred.

Can’t wait to start planning this weekend!

-Kristin

8 thoughts on “Talking Points – 2D Geometry

  1. Keith Howell

    I love how you are engaging and empowering your students through the learning process. It is so important for children to understand concepts and ideas rather than just getting to an answer. I enjoyed reading your reflecting on the activity and student samples. Thanks for sharing! Have a great week!

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  2. Pingback: Always, Sometimes, Never….Year 2 | Math Minds

  3. Pingback: Pre/Post Assessment Reflection | Math Minds

  4. Pingback: Fraction Talking Points: 3rd Grade | Math Minds

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