# Lesson 13

Día 2 de centros

## Warm-up: Conversación numérica: Hasta 20 (10 minutes)

### Narrative

The purpose of this Number Talk is to elicit understandings students have for adding and subtracting within 20 using the strategy of making a ten.

### Launch

• Display one expression.
• “Hagan una señal cuando tengan una respuesta y puedan explicar cómo la obtuvieron” // “Give me a signal when you have an answer and can explain how you got it.”
• 1 minute: quiet think time

### Activity

• Keep expressions and work displayed.
• Repeat with each expression.

### Student Facing

Encuentra mentalmente el valor de cada expresión.

• $$10 + 4$$
• $$9 + 4$$
• $$9 + 6$$
• $$15 – 6$$

### Activity Synthesis

• “¿Alguien pensó en el problema de otra forma?” // “Did anyone approach the problem in a different way?”

## Activity 1: Centros: Momento de escoger (20 minutes)

### Narrative

The purpose of this activity is for students to choose from activities that offer practice working with tens and ones. Students choose from any stage of previously introduced centers.

• Grab and Count
• Five in a Row
• Check It Off

### Required Materials

Materials to Gather

### Required Preparation

• Gather materials from previous centers:
• Grab and Count, Stage 2
• Five in a Row, Stages 1–4
• Check It Off, Stages 1–3

### Launch

• Groups of 2
• “Ahora van a escoger centros de los que ya conocemos” // “Now you 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.

Agarra y cuenta

Cinco en línea

Márcalo

### Activity Synthesis

• “Han está jugando ‘Márcalo’. Él escoge los números 70 y 20. ¿Qué números podría marcar?” // “Han is playing Check It Off. He picks the numbers 70 and 20. What numbers could he check off?” (50 or 90)

## Activity 2: Centros: Momento de escoger (20 minutes)

### Narrative

The purpose of this activity is for students to choose from activities that offer practice adding and subtracting within 20. Students choose from any stage of previously introduced centers.

• How Close?
• Number Puzzles
• Shake and Spill

### Required Materials

Materials to Gather

### Required Preparation

• Gather materials from previous centers:
• How Close, Stages 1 and 2
• Number Puzzles, Stages 1 and 2
• Shake and Spill, Stages 3–5

### Launch

• Groups of 2
• “Ahora van a escoger centros de los que ya conocemos” // “Now you 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.

¿Qué tan cerca?

Acertijos numéricos

Revuelve y saca

### Activity Synthesis

• Display 8, 4, 1, 7, 5.
• “Priya está jugando ‘Qué tan cerca’. Va a elegir 3 números. ¿Cuáles debería escoger para acercarse a 20?” // “Priya is playing How Close. Which three numbers should she choose to get close to 20?”

## Lesson Synthesis

### Lesson Synthesis

“¿Cómo les fue trabajando con su pareja en los centros? ¿Qué salió bien? ¿Qué podemos mejorar?” // “How did you and your partner work together during centers? What went well? What can we continue to work on?”