Looking at the Similarities and Differences

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SWBAT: Identify the differences between a square and a triangle. SWBAT: Identify the rule by which a group of shapes is categorized.

Big Idea

La, La, La, La, La, sing a happy song! You will be signing like a Smurf as students use their new founded knowledge of shape characteristics to participate in a whole group discussion and to successfully participate in geometric learning.

Warm Up

5 minutes

Using the established Quick Flash Routine, flash a shape (see section resource) using the document camera.  Have the students record the shape and then describe how they remembered what to record.  Repeat with one or two more shapes.

Discussion How are the Similar? How are They Different

15 minutes

*Advanced preparation:  Have the square and triangle posters (shape talk) that you made (in a previous lesson) available for the discussion (see picture in resources section: Comparing Shapes.  

I start by holding up a square and a right triangle (from the power polygon set).  

How are these two shapes similar? I elicit responses and also refer the children to the observations that they made on the shape posters (in a previous activity).  I then ask them: How are they Different? and again elicit responses.  However, I will now add the differences to the shape posters as well.  The CCSS ask that 1st graders try to communicate precisely to others. They try to use clear definitions in discussion with others and in their own reasoning (CCSS.Math.Practice.MP6).  The discussion allows students to communicate their thinking by using established ideas/concepts from previous lessons.

I want to try and bring in the use of correct vocabulary (sides, vertices, angles,) as much as possible during the discussion.  The CCSS require that students distinguish between defining attributes of shapes (CCSS.Math.Content.1.G.A.1).  This activity is asking students to do just that.  The students are using their knowledge of the attributes and vocabulary to describe the similarities and differences.


Reflection Videos

3 minutes


Click here to view a few more examples of student thinking. 


What's My Rule?

20 minutes

I will play the What's My Rule activity that was introduced in a previous lesson.  However, I want to be a little more advanced with my rules today. Possible rules can be: *Quadrilaterals, Shapes with All Equal Sides, Triangles, etc.

Center Time

35 minutes

The students will have an opportunity to engage themselves in three different learning opportunities during center time.

1.  Triangles and Quadrilaterals on Array Paper:  The students circle three dots for triangle vertices and four dots for quadrilateral vertices.  For a more detailed description, please refer back to yesterdays lesson, in the center time section.

2.  Creating Geoboard Triangles:  Click here for a description from the previous lesson.  Look under the center time section.

 3.  Power Polygons:  Click here for a description from the previous lesson.  Look under the center time section.