# Lesson 19

Encontremos el número con el que se forma 10 (optional)

## Warm-up: Cuántos ves: Formemos 10 (10 minutes)

### Narrative

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

### 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 ver diferentes maneras de formar 10?” // “How does the 10-frame help you see different ways to make 10?” (I know that there are 5 squares in each row and 10 squares altogether. I can look at the empty squares to figure out how many more are needed to make 10.)

## Activity 1: Coloreemos el número con el que se forma 10 (15 minutes)

### Narrative

The purpose of this activity is for students to practice finding the number that makes 10 when added to a given number. They can represent this number on their bead tool, fingers, or 10-frame and determine the number that needs to be added to make 10 (MP5).

MLR8 Discussion Supports. During partner work time, invite each partner to read each equation aloud. Listen for and clarify questions about the equations.
Engagement: Develop Effort and Persistence. Chunk the board in the student-facing task into more manageable parts. Check in with students after using a smaller version of the board.
Supports accessibility for: Organization, Attention

### Required Preparation

• Students can use their bead tool from a previous lesson.

### Launch

• Groups of 2
• “Van a jugar un juego con su compañero. Un compañero va a colorear uno de los cuadrados del tablero. El otro compañero tendrá que averiguar cuál número se necesita para formar 10 con ese número y lo debe colorear del mismo color. Sigan jugando hasta que coloreen todas las parejas. En cada ronda, intercambien roles y cambien de color” // “You are going to play a game with your partner. One partner will color in one of the squares on the board. The other partner will have to figure out which number you need to make 10 with that number and color it in with the same color. Keep playing until you color in all of the matches. Switch partners and colors each time.”

### Activity

• 12 minutes: partner work time
• “Escojan su manera favorita de formar 10 y completen la ecuación” // “Choose your favorite way to make 10 and fill in the equation.”
• 1 minute: independent work time

### Student Facing

• Compañero A: colorea 1 número.
• Compañero B: colorea del mismo color el número con el que se forma 10.
• Intercambien roles, cambien de color y repitan estos pasos.

Escoge tu manera favorita de formar 10.
Completa la ecuación.

$$10 = \underline{\hspace{1.1 cm}} + \underline{\hspace{1.1 cm}}$$

### Activity Synthesis

• Invite students to share how they figured out the number needed to make 10.
• Display $$10 = 8 + \underline{\hspace{1 cm}}$$.
• “Elena estaba completando su ecuación. Ella solo escribió el número que coloreó su compañero. Escribió: $$10 = 8 + \underline{\hspace{1 cm}}$$. ¿Qué número coloreó Elena? ¿Cómo lo saben?” // “Elena was filling in her equation. She only filled in the number her partner colored. She wrote $$10 = 8 + \underline{\hspace{1 cm}}$$. What number did Elena color in? How do you know?” (She colored in 2. 8 and 2 make 10.)

## Activity 2: Sumemos para formar 10 (10 minutes)

### Narrative

The purpose of this activity is for students to find the number that makes 10 when added to a given number. Students fill in equations with a missing addend. Students choose appropriate tools strategically as they choose from tools used throughout the year (MP5). For some equations, students may not need a tool because they know the composition to make 10, which is discussed in the activity synthesis.

### Required Materials

Materials to Gather

### Required Preparation

• Students can use their bead tool from a previous lesson.

### Launch

• Groups of 2
• “En cada caso, completen la ecuación para que muestre una manera de formar 10” // “Fill in each equation so that they show a way to make 10.”

### Activity

• 4 minutes: independent work time
• 4 minutes: partner work time

### Student Facing

Completa las ecuaciones para mostrar maneras de formar 10.

• $$10 = 9 + \underline{\hspace{1 cm}}$$

• $$10 = 3 + \underline{\hspace{1 cm}}$$

• $$10 = 5 + \underline{\hspace{1 cm}}$$

• $$10 = 4 + \underline{\hspace{1 cm}}$$

• $$10 = 8 + \underline{\hspace{1 cm}}$$

• $$10 = 7 + \underline{\hspace{1 cm}}$$

### Activity Synthesis

• “¿Cómo escogieron la herramienta que les ayudaría a averiguar cuál número necesitaban para formar 10? ¿Hubo problemas en los que no tuvieron que usar ninguna herramienta para averiguar la respuesta?” // “How did you choose which tool to use to help you figure out which number you needed to make 10? Were there any problems that you didn’t need to use a tool to figure out?”

## 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.

• Shake and Spill
• Number Race
• Grab and Count
• What's Behind My Back?
• Pattern Blocks

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:
• Shake and Spill
• Number Race
• Grab and Count
• What's Behind My Back?
• Pattern Blocks

### 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.

Revuelve y saca

Carrera con números

Agarra y cuenta

¿Qué hay a mis espaldas?

Fichas geométricas

### Activity Synthesis

• “¿Qué pueden hacer que los ayude a trabajar con éxito en los centros? ¿Qué pueden hacer sus compañeros para ayudarlos a trabajar con éxito? ¿Qué puede hacer su profesor?” // “What can you do to help you be successful when working in centers? What can your partner(s) do to help you be successful? What can your teacher do?”

## Lesson Synthesis

### Lesson Synthesis

“Hoy averiguamos qué número necesitábamos para formar 10 y mostramos con ecuaciones las maneras de formar 10” // “Today we figured out what number we needed to make 10 and showed the ways to make 10 with equations.”

“Díganle a su compañero una manera de formar 10. Díganle al menos 2 maneras en las que pueden mostrarlo” // “Tell your partner one way to make 10. Tell them at least 2 ways that you can show it.” (5 and 5. I can show 5 fingers and 5 fingers. 7 and 3. I can show 7 red counters and 3 yellow counters on a 10-frame.)