# Lesson 2

Contemos y comparemos colecciones (optional)

## Warm-up: Cuántos ves: 10 y algunos más (10 minutes)

### Narrative

The purpose of this How Many Do You See is for students to subitize or use grouping strategies to describe the images they see.

When students use the structure of the 10-frame to determine how many dots there are they look for and make sure of structure (MP7).

### Launch

• Groups of 2
• “¿Cuántos ven? ¿Cómo lo saben?, ¿qué ven?” // “How many do you see? How do you see them?”
• Flash the image.
• 30 seconds: quiet think time

### Activity

• Display the image.
• “Discutan con su compañero cómo pensaron” // “Discuss your thinking with your partner.”
• 1 minute: partner discussion
• Record responses.
• Repeat for each image.

### Student Facing

¿Cuántos ves?
¿Cómo lo sabes?, ¿qué ves?

### Activity Synthesis

• “¿Cómo les ayuda el tablero de 10 a descifrar cuántos puntos hay?” // “How is the 10-frame helpful when figuring out how many dots there are?” (I know that there are 10 dots on the 10-frame and 10 and 5 is 15. I start counting at 10 and count the rest of the dots.)

## Activity 1: Contemos colecciones (10 minutes)

### Narrative

The purpose of this activity is for students to count collections of up to 20 objects and represent their count with drawings and numbers (MP2).

Action and Expression: Internalize Executive Functions. Invite students to plan a strategy, including the tools they will use to figure out how many objects are in their collection.
Supports accessibility for: Conceptual Processing, Organization

### Required Materials

Materials to Gather

### Required Preparation

• Each student needs a collection of 11–20 objects.

### Launch

• Give each student a collection of objects and access to 10-frames.

### Activity

• “¿Cuántos objetos hay en su colección? Muestren cómo pensaron. Usen dibujos, números o palabras” // “How many objects are in your collection? Show your thinking using drawings, numbers, or words.”
• 3 minutes: independent work time
• “Si no lo han hecho todavía, escriban un número que muestre cuántos objetos hay en su colección” // “If you haven’t already, write a number to show how many objects are in your collection.”
• 2 minutes: independent work time
• Monitor for students who organize their collections in different ways to share in the synthesis.

### Student Facing

¿Cuántos objetos hay en tu colección?
Muestra cómo pensaste. Usa dibujos, números o palabras.

_______________

### Activity Synthesis

• Invite 2–3 previously selected students to share how they organized their objects.
• “¿En qué se parecen las formas en las que están organizados los objetos? ¿En qué son diferentes?” // “What is the same about how the objects are organized? What is different?”
• Then, for each collection shared, ask: “¿Cómo supo _____ que había __ objetos en su colección?” // “How did _____ know there were __ objects in their collection?”

## Activity 2: Comparemos colecciones (15 minutes)

### Narrative

The purpose of this activity is for students to compare groups of up to 20 objects. Students count and represent a new collection of objects and then determine which collection has more objects. If a student's collection was shared in the previous activity synthesis, give that student a new collection of objects for this activity.

MLR8 Discussion Supports. Invite students to pair gestures with verbal explanations as they figure out which collection has fewer objects.

### Required Preparation

• Students need their collection of objects and representation from the previous activity.

### Launch

• Groups of 2
• “Intercambien su colección con su pareja” // “Switch your collection with your partner.”

### Activity

• “¿Cuántos objetos hay en su nueva colección? Muestren cómo pensaron. Usen dibujos, números o palabras” // “How many objects are in your new collection? Show your thinking using drawings, numbers, or words.”
• 3 minutes: independent work time
• “Si no lo han hecho todavía, escriban un número que muestre cuántos objetos hay en su colección” // “If you haven’t already, write a number to show how many objects are in your collection.”
• 2 minutes: independent work time
• “Comparen su colección con su pareja. Descifren cuál colección tiene menos objetos” // “Compare your collection with your partner. Figure out which collection has fewer objects.”
• 3 minutes: partner work time
• Monitor for a pair of students who both used a 10-frame to organize and represent their collection and then used the 10-frame to help them compare collections.

### Student Facing

¿Cuántos objetos hay en tu colección?
Muestra cómo pensaste. Usa dibujos, números o palabras.

_______________

### Activity Synthesis

• Invite previously identified students to share.
• “¿Quién tiene la colección con más objetos? ¿Cómo lo saben?” // “Whose collection has more objects? How do you know?” (_____ has more. They both have a full 10-frame so I just looked at the other objects.)

## Activity 3: Centros: Momento de escoger (20 minutes)

### Narrative

The purpose of this activity is for students to choose from activities that offer practice with number and shape concepts. Students choose from 5 centers introduced in previous units. Students can choose to work at any stage of the centers.
• Less, Same, More
• Math Fingers
• Tower Build
• Math Stories
• Which One
Students will continue to choose from these centers in upcoming lessons. Keep the materials from each center organized to use each day.

### Required Materials

Materials to Gather

### Required Preparation

• Gather materials from:
• Less, Same, More
• Math Fingers
• Tower Build
• Math Stories
• Which One

### Launch

• Groups of 2
• “Hoy vamos a escoger centros de los que ya conocemos” // “Today we are going to choose from centers we have already learned.”
• Display the center choices in the student book.
• “Piensen qué les gustaría hacer primero” // “Think about what you would like to do first.”
• 30 seconds: quiet think time

### Activity

• Invite students to work at the center of their choice.
• 8 minutes: center work time
• “Escojan qué les gustaría hacer ahora” // “Choose what you would like to do next.”
• 8 minutes: center work time

### Student Facing

Escoge un centro.

Menos, lo mismo, más

Dedos matemáticos

Construcción de torres

Historias matemáticas

¿Cuál es?

### Activity Synthesis

• “Si le fueran a enseñar a otro estudiante cómo jugar el centro ______, ¿qué le dirían o qué le mostrarían?” // “If you were going to teach another student how to play ________ center, what would you tell them or show them?”

## Lesson Synthesis

### Lesson Synthesis

Draw two representations or display two similar student-created representations.
“Comparen los grupos de objetos. Expliquen cómo saben cuál grupo tiene más objetos” // “Compare the groups of objects. Explain how you know which group has more objects.” (I know that 16 is more than 13. I see 10 on top and 10 in the 10-frame, so I looked at the extra circles. 6 is more than 3, so that one must have more.)