# Lesson 5

Círculos y triángulos

## Warm-up: Cuál es diferente: Características de las figuras (10 minutes)

### Narrative

This warm-up prompts students to carefully analyze and compare the attributes of four shapes. In making comparisons, students have a reason to use language precisely (MP6). The activity also enables the teacher to hear the terminologies students know and how they talk about attributes of shapes.

### Launch

• Groups of 2
• Display the image.
• “Escojan una que sea diferente. Prepárense para compartir por qué es diferente” // “Pick one that doesn’t belong. Be ready to share why it doesn’t belong.”

### Activity

• 30 seconds: quiet think time
• 30 seconds: partner discussion
• Share and record responses.

### Student Facing

¿Cuál es diferente?

### Student Response

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### Activity Synthesis

• Display image C.
• “¿En qué es diferente esta figura?” // “What is different about this shape?” (It has a side that is curved.)
• “¿Conocen alguna otra figura que tenga lados curvos?” // “Do you know any other shapes that have curved sides?” (A circle.)

## Activity 1: Coloreemos círculos y triángulos (10 minutes)

### Narrative

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 may 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 triangles or circles, particularly distactors, 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.

MLR8 Discussion Supports. To support the transfer of new vocabulary to long term memory, invite students to chorally repeat these words in unison 1–2 times: circles, triangles.
Advances: Listening, Speaking
Representation: Access for Perception. Synthesis: Students might need extra support determining that the oval and the pizza slice shapes are not circles or triangles. Hold up a triangle and circle next to the shapes to visually show that the oval and pizza slice shapes do not match the triangle and circle.
Supports accessibility for: Visual-Spatial Processing

### Required Materials

Materials to Gather

### Required Preparation

Each student needs at least 2 different colored crayons or colored pencils.

### Launch

• Groups of 2
• Give each student access to 2 different color crayons or colored pencils.
• Display the image from the book.
• “Mai puso sus figuras en 2 grupos. ¿Qué observan? ¿Por qué creen que Mai puso estas figuras juntas?” // “Mai put her shapes into 2 groups. What do you notice? Why do you think Mai put these shapes together?”
• 30 seconds: quiet think time
• Share responses.
• “¿Qué nombre le podemos dar a cada grupo?” // “What can we name each group?”
• 30 seconds: quiet think time
• 30 seconds: partner discussion
• Share responses.
• “Podemos llamar círculos a este grupo de figuras. Todas las figuras de este grupo son círculos. Podemos llamar triángulos a este grupo de figuras porque todas las figuras de este grupo son triángulos” // “We can call this group circles. All of the shapes in this group are circles. We can call this group triangles because all of the shapes in this group are triangles.”
• “¿Qué saben sobre los círculos?” // “What do you know about circles?”
• 30 seconds: quiet think time
• 30 seconds: partner discussion
• Share and record responses.
• “¿Qué saben sobre los triángulos?” // “What do you know about triangles?”
• 30 seconds: quiet think time
• 30 seconds: partner discussion
• Share and record responses.
• Display student workbook.
• “Coloreen con un color todos los círculos que encuentren. Después, coloreen con otro color todos los triángulos que encuentren” // “Color all of the circles that you find with 1 color. Then color all of the triangles that you find with another color.”

### Activity

• 4 minutes: independent work time
• “Escojan un triángulo que hayan coloreado. Cuéntenle a su compañero 1 cosa que sepan sobre esa figura” // “Choose 1 triangle that you colored in. Tell your partner 1 thing that you know about that shape.”
• 30 seconds: quiet think time
• 30 seconds: partner discussion
• “Escriban un número que muestre cuántos triángulos colorearon. Escriban un número que muestre cuántos círculos colorearon” // “Write a number to show how many triangles you colored. Write a number to show how many circles you colored.”
• 1 minute: independent work time
• “¿Colorearon más triángulos que círculos? ¿Como lo saben?” // “Did you color more triangles or more circles? How do you know?”
• 30 seconds: quiet think time
• 30 seconds: partner discussion

### Student Response

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### Activity Synthesis

• Display shape from student book or draw shape:
• “¿Colorearon esta figura? ¿Por qué si o por qué no?” // “Did you color this shape? Why or why not?” (I didn’t color the shape. It looks like a triangle but one of the sides is round.)
• Display shape from student book or draw shape:
• “¿Colorearon esta figura? ¿Por qué si o por qué no?” // “Did you color this shape? Why or why not?” (I didn’t color this shape. It looks like a circle but it is stretched out.)

## Activity 2: Clasificación de triángulos (15 minutes)

### Narrative

The purpose of this activity is for students to begin to distinguish triangles from other shapes. 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 with their group which group a shape should be placed in, students informally describe the attributes of the shape (MP6).

### Required Materials

Materials to Copy

• Triangle Sort Cards

### Required Preparation

• Cut out triangle cards from the blackline master. Each group of 4 needs 1 set of cards.

### Launch

• Groups of 4
• Give each group a set of cards.
• “Juntos, clasifiquen las figuras en 2 grupos. Pongan las figuras que son triángulos en el lado izquierdo de su página. Pongan las figuras que no son triángulos en el lado derecho de su página. Cuando pongan una figura, cuéntenle a su grupo por qué creen que la figura debe estar en ese grupo” // “Work with your group to sort the shapes into 2 groups. Put the shapes that are triangles on the left side of your page. Put the shapes that are not triangles on the right side of your page. When you place a shape, tell your group why you think the shape belongs in that group.”

### Activity

• 4 minutes: small-group work time
• Monitor for students who discuss attributes of triangles when sorting.
• “Escriban un número que muestre cuántas figuras hay en cada grupo” // “Write a number to show how many shapes are in each group.”
• 1 minute: independent work time
• “Caminen por el salón para ver cómo organizaron sus figuras los demás compañeros. ¿Las organizaron de la misma manera que ustedes?” // “Walk around to see how the other groups organized their shapes. Did they organize them the same way that your group did?”
• 6 minutes: work time

### Student Facing

Pongamos las figuras en 2 grupos.

Triángulos

No son triángulos

### Student Response

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### Advancing Student Thinking

If students put shapes other than triangles into the group of triangles, consider asking:

• “¿Como escogiste en qué grupo poner esta figura?” // “How did you choose which group to put this shape in?”
• “¿Qué tienen en común todas las figuras de este grupo?” // “What is alike, or the same, about all of the shapes in this group?”

### Activity Synthesis

• Display cards O, K, and G next to each other.
• “Noah dice que la figura del medio no es un triángulo porque apunta hacia abajo y los triángulos tienen que apuntar hacia arriba. ¿Están de acuerdo con Noah? ¿Por qué si o por qué no?” // “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?“

## Activity 3: Conozcamos “Contar colecciones: Hasta 20” (20 minutes)

### Narrative

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 collection.

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

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

### Required Materials

Materials to Gather

### Required Preparation

• Gather materials from:
• Which One, Stage 1
• Picture Books, Stages 1-3
• Bingo, Stages 1 and 2
• Shake and Spill, Stages 1 and 2

### Launch

• Groups of 2
• “Hoy vamos a conocer un centro nuevo llamado ‘Contar colecciones’. En parejas, descifren cuántos objetos hay en su colección. Usen las herramientas si les ayudan. Cuando ambos estén de acuerdo en cuántos objetos hay en la colección, pueden escoger otra colección” // “We are going to learn a new center called Counting Collections. Work with your partner to figure out how many objects are in your collection. Use the tools if they are helpful. When you and your partner agree on how many objects are in the collection, you can choose another collection.”

### Activity

• 8 minutes: partner work time
• “Ahora pueden escoger otro centro. También pueden seguir trabajando en el centro ‘Contar colecciones’” // “Now you can choose another center. You can also continue doing Counting Collections.”
• Display the center choices in the student book.
• Invite students to work at the center of their choice.
• 10 minutes: center work time
• If time, invite students to choose another center.

### Student Facing

Escoge un centro.

Contar colecciones

Cuál es

Libros de imágenes

Bingo

Revuelve y saca

### Activity Synthesis

• “¿Hicieron lo mismo que su pareja para descubrir cuántos objetos había en su colección? ¿Qué hicieron parecido? ¿Qué hicieron diferente?” // “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?”

## Lesson Synthesis

### Lesson Synthesis

“Hoy les dimos nombre a los círculos y a los triángulos. ¿En qué son diferentes los círculos y los triángulos? ¿Qué palabras pueden usar para describir los triángulos? ¿Qué palabras pueden usar para describir los círculos?” // “Today we named circles and triangles. How are circles and triangles different? What words can you use to describe triangles? What words can you use to describe circles?”

“¿En qué lugares de su casa ven círculos u objetos que se parecen a los círculos? ¿En qué lugares ven triángulos?” // “Where at home do you see circles or objects that look like circles? Where do you see triangles?”

## Cool-down: Unidad 3, punto de chequeo de la sección A (0 minutes)

### Cool-Down

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