# Lesson 22

Día 4 de centros

### Narrative

The purpose of this True or False is to elicit insights students have about numbers being represented in different ways. The reasoning students do here deepens their understanding of how numbers can be composed and decomposed in different ways using tens and ones.

### Launch

• Display one statement.
• “Hagan una señal cuando sepan si la afirmación es verdadera o no, y puedan explicar cómo lo saben” // “Give me a signal when you know whether the statement is true and can explain how you know.”
• 1 minute: quiet think time

### Activity

• Share and record answers and strategy.
• Repeat with each statement.

### Student Facing

Prepárate para explicar tu razonamiento.

• $$92 = 90 + 2$$

• $$90 + 2 > 80 + 12$$

• $$20 + 13 < 30 + 13$$

### Activity Synthesis

• “¿Cómo pueden decidir si cada una es verdadera o falsa sin encontrar el valor de cada lado?” // “How can you determine whether each is true or false without finding the value of each side?”
• If needed, ask “¿Cómo pueden usar lo que saben sobre decenas y unidades para saber si la afirmación es verdadera o falsa?” // “How can you use what you know about tens and ones to help you know if it is true or false?” (I can compare the number of tens first, then compare ones.)

## Activity 1: Conozcamos “El número secreto: Números de dos dígitos” (15 minutes)

### Narrative

The purpose of this activity is for students to learn a new center called Mystery Number. Each student has a mystery number. They give clues to their partner based on sentence stems. After each clue, the partner guesses the mystery number. Players earn points based on how many clues they need to identify the mystery number. The player with the lowest score after five rounds wins.

### Required Materials

Materials to Gather

Materials to Copy

• Mystery Number Stage 1 Directions, Spanish

### Launch

• Groups of 2
• Give each group a set of cards and directions.
• “Vamos a conocer un nuevo centro que se llama ‘El número secreto’” // “We are going to learn a new center called Mystery Number.”

### Activity

• 10 minutes: partner work time

### Activity Synthesis

• “¿Cuáles pistas hicieron que el número de su pareja fuera más fácil de adivinar?” // “Which clues made your partner’s number easiest to guess?”

## Activity 2: Centros: Momento de escoger (25 minutes)

### Narrative

The purpose of this activity is for students to choose from activities that offer practice working with two-digit numbers. Students choose from previously introduced centers.

• Mystery Number
• Get Your Numbers in Order
• Greatest of Them All

### Required Materials

Materials to Gather

### Required Preparation

• Gather materials from previous centers:
• Mystery Number, Stage 1
• Get Your Numbers in Order, Stage 1
• Greatest of Them All, Stage 1

### Launch

• Groups of 2
• “Vamos a escoger centros de los que ya conocemos” // “We are going to choose from centers we have already learned.”
• Display the student page.
• “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.
• 10 minutes: center work time
• “Escojan qué les gustaría hacer ahora” // “Choose what you would like to do next.”
• 10 minutes: center work time

### Student Facing

Escoge un centro.

El número secreto

Ordena tus números

El más grande de todos

### Activity Synthesis

• “¿En qué se parecían los dos centros en los que trabajaron? ¿En qué eran diferentes?” // “How were the two centers you worked on the same? How were they different?”

## 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?”