# Lesson 2

## Warm-up: Observa y pregúntate: Más manzanas (10 minutes)

### Narrative

The purpose of this warm-up is to elicit the idea that many different questions could be asked about a situation, which will be useful when students solve problems in a later activity.

### Launch

• Groups of 2
• Display the image.
• “¿Qué observan? ¿Qué se preguntan?” // “What do you notice? What do you wonder?”
• 1 minute: quiet think time

### Activity

• “Discutan con su compañero lo que pensaron” // “Discuss your thinking with your partner.”
• 1 minute: partner discussion
• Share and record responses.

### Student Facing

¿Qué observas? ¿Qué te preguntas?

### Activity Synthesis

• If not mentioned in students’ responses, ask: “¿Qué preguntas matemáticas podemos hacer sobre esta imagen?” // “What mathematical questions could we ask about this picture?” (How many apples are in each box? Are there more apples in the boxes than on the trees? How many apples are in the boxes altogether?)

## Activity 1: ¿Cuántas manzanas? (15 minutes)

### Narrative

The purpose of this activity is for students to represent and solve “how many in each group?” problems using whatever strategy and visual representation make sense to them. Students create a poster of their solution to the first problem with a partner. In the next activity, they participate in a gallery walk of the posters.

Monitor for students who represent the situation with:

• concrete objects: putting 20 cubes into 4 groups one by one
• drawings of objects: drawing 20 apples and then splitting them into 4 groups
• arrays: drawing 4 rows with one apple in each row to reach 20
Engagement: Develop Effort and Persistence. Chunk this task into more manageable parts. Check in with students to provide feedback and encouragement after each chunk (problem).
Supports accessibility for: Attention

### Required Materials

Materials to Gather

### Launch

• Groups of 2
• “Hablen con su compañero sobre cómo podrían resolver estos problemas” // “Turn and talk to your partner about how you might solve these problems.”
• 1–2 minutes: partner discussion

### Activity

• “Resuelvan estos problemas. Usen objetos, un dibujo o un diagrama para mostrar cómo pensaron” // “Solve these problems and show your thinking using objects, a drawing, or a diagram.”
• 5–7 minutes: independent work time
• As student work, consider asking:
• “¿Cómo pueden representar lo que están pensando?” // “How can you represent what you are thinking?”
• “¿En qué parte de su trabajo pueden ver las cajas?” // “Where can you see the boxes in your work?”
• “¿En qué parte de su trabajo pueden ver cuántas manzanas hay en cada caja?” // “Where can you see how many apples are in each box in your work?”
• Monitor for students who solve the first problem in the same way. Arrange them into groups of 2 to create a poster together.
• “Ahora van a hacer un póster para mostrar cómo pensaron en el primer problema” // “Now you are going to create a poster to show your thinking on the first problem.”
• “Van a trabajar con un compañero que haya resuelto el problema de la misma forma que ustedes” // “You are going to work with a partner who solved the problem in the same way you did.”
• Give each group tools for creating a visual display.
• 5–7 minutes: partner work time

### Student Facing

Resuelve cada problema. Muestra cómo pensaste. Usa objetos, un dibujo o un diagrama.

1. Si 20 manzanas se empacan en 4 cajas y en cada caja hay el mismo número de manzanas, ¿cuántas manzanas hay en cada caja?

2. Si 36 manzanas se empacan en 6 cajas y en cada caja hay el mismo número de manzanas, ¿cuántas manzanas hay en cada caja?

3. Si 45 manzanas se empacan en 9 cajas y en cada caja hay el mismo número de manzanas, ¿cuántas manzanas hay en cada caja?

### Student Response

If students don’t find a solution to the problems, consider asking: “¿De qué se trata este problema?” // “What is this problem about?” and “¿Cómo podrías representar el problema?” // “How could you represent the problem?”

### Activity Synthesis

• Display posters around the room.

## Activity 2: Recorrido por el salón (10 minutes)

### Narrative

The purpose of this activity is for students to consider what is the same and what is different about the ways that they solved a “how many in each group?” problem in the previous activity. As students visit the posters, identify 2–3 students who show particularly well that this problem is about finding how many there are in each group. Select them to share in the next activity.

• Groups of 2

### Activity

• “Cuando estén viendo los pósteres con su compañero, discutan en qué se parecen y en qué se diferencian las ideas que se muestran en los pósteres” // “As you visit the posters with your partner, discuss what is the same and what is different about the thinking shown on each poster.”
• 5–7 minutes: gallery walk

### Student Facing

Con tu compañero, ve a ver los pósteres alrededor del salón. Discute con tu compañero en qué se parecen y en qué se diferencian las ideas que se muestran en los pósteres.

### Activity Synthesis

• Give students a chance to ask questions they have about any posters.
• “¿En qué se parecen las ideas que se muestran en los pósteres?” // “What is the same about the thinking shown on the posters?”
• “¿En qué se diferencian las ideas que se muestran en los pósteres?” // “What is different about the thinking shown on the posters?”

## Activity 3: Todas las manzanas (10 minutes)

### Narrative

The purpose of this activity is for students to consider what is the same and what is different about the “how many groups?” and “how many in each group?” problems they solved in a previous lesson and in this lesson. The discussion should highlight that in “how many groups?” problems we know the size of each group and in “how many in each group?” problems we know how many groups there are. In order to describe how the problems are the same and how they are different, students attend to the structure of the problems, that is what is given in each situation and what is unknown (MP7).

MLR7 Compare and Connect. Synthesis: Lead a discussion comparing, contrasting, and connecting the different representations. Ask, “¿Qué palabras específicas o qué lenguaje les ayudó a entender cómo resolver los problemas? ¿Hay otros detalles o lenguaje sobre el que tengan preguntas?” // “What specific words or language helped you understand how to solve the problems? Are there any additional details or language that you have questions about?” To amplify student language, and illustrate connections, follow along and point to the relevant parts of the displays as students speak.

### Required Preparation

• Gather the 2–3 posters  from the previous lesson and this lesson that highlight counting the groups in a “how many groups?” problem and finding how many in each group in a “how many in each group?” problem.

### Launch

• Groups of 2
• Display the problems.
• Display the 2-3 previously selected posters for each problem.

### Activity

• “Estos son dos problemas en los que trabajamos. Ayer hicimos pósteres para el primero y hoy hicimos pósteres para el segundo” // “Here are two problems we’ve worked on. Yesterday we made posters for the first one and today we made posters for the second one.”
• “Estos son algunos pósteres para cada problema” // “Here are a few posters for each problem.”
• “Discutan con su compañero en qué se parecen estos problemas y en qué se diferencian. También hablen sobre en qué se parecen y en qué se diferencian las formas de representar y resolver estos problemas” // “Talk to your partner about how these problems are alike and how they are different. Also talk about what is alike and what is different about how the problems are represented and solved.”
• 3-5 minutes: partner discussion

### Student Facing

Si 24 manzanas se ponen en cajas y en cada caja se ponen 8 manzanas, ¿cuántas cajas hay?

Si 20 manzanas se empacan en 4 cajas y cada caja tiene el mismo número de manzanas, ¿cuántas manzanas hay en cada caja?

Discute con tu compañero:

• ¿En qué se parecen estos problemas?
• ¿En qué se diferencian?
• ¿En qué se parecen y en qué se diferencian las formas de representar y resolver estos problemas?

### Activity Synthesis

• “¿Qué observaron ustedes y su compañero que era parecido?” // “What did you and your partner notice was alike?”
• “¿Qué observaron ustedes y su compañero que era diferente?” // “What did you and your partner notice was different?”
• Share and record responses.
• As students share, encourage them to use the posters to show examples of what they notice.

## Lesson Synthesis

### Lesson Synthesis

“Ayer, resolvimos problemas en los que preguntaban cuántos grupos podíamos hacer. Hoy resolvimos problemas en los que preguntaban cuántas cosas hay en cada grupo. Ambas ideas se conocen con el nombre de división” // “Yesterday, we solved problems that asked about how many groups we could make. Today we solved problems that asked about how many things are in each group. Both of these ideas are division.”

“La división es encontrar el número de grupos o encontrar el tamaño de cada grupo cuando repartimos algo en grupos de igual tamaño” // Division is finding the number of groups or finding the size of each group when we share into groups of equal size.”