The purpose of this activity is for students to identify examples of circles and triangles. The geometric terms circle and triangle are formally introduced, though some students may already be familiar with the terms and have heard or used them in previous lessons. This activity exposes students to a wider variety of circles and triangles than they may have seen previously, which encourages students to expand their concepts of the shapes. Students may incorrectly identify some shapes as circles or triangles, particularly distractors, such as a shape that looks like a triangle but has 4 sides. These shapes can be discussion points and are expected throughout kindergarten. Students distinguish between defining and non-defining attributes of shapes in grade 1.

• Display the shape from student book, or draw the shape:

  

• “Did you color this shape? Why or why not?” (I didn’t color the shape. It looks like a triangle but 1 side is round.)
• Display the shape from the student book, or draw the shape:

  

• “Did you color this shape? Why or why not?” (I didn’t color this shape. It looks like a circle but it's stretched out.)

The purpose of this activity is for students to begin to distinguish triangles from other shapes. This sorting task gives students opportunities to analyze shapes closely and make connections (MP7). By working with variants and non-examples of triangles, students begin to develop their understanding of what makes a shape a triangle. Students may more easily identify equilateral triangles as triangles but may also identify other examples as triangles. When students discuss which group a shape should be placed in, students informally describe the attributes of the shape (MP6).

• “How did you choose which group to put this shape in?”
• “What is alike, or the same, about all shapes in this group?”

• Display Cards O, K, and G next to each other.
• “Noah says that the shape in the middle is not a triangle because it is pointing down and triangles have to point up. Do you agree with Noah? Why or why not?“

The purpose of this activity is for students to learn Stage 1 of the Counting Collections center. Most students should be given collections with 6–10 objects. Based on formative assessment data collected in previous sections, adjust the number of objects in collections for individual students. Provide students with counting mats and 5-frames to help them accurately count or organize their collections. Students use appropriate tools strategically as they choose which tools help them count their collections (MP5). In a future variation of this center, students will draw pictures or write numbers to represent their collections.

After they participate in the center, students choose from any stage of previously introduced centers:

• Which One?
• Picture Books
• Bingo
• Shake and Spill

• “Did you and your partner do the same thing to figure out how many objects were in your collection? What did you do the same? What did you do differently?”