# Lesson 6

Problemas sobre mascotas

## Warm-up: Observa y pregúntate: El acuario (10 minutes)

### Narrative

The purpose of this warm-up is for students to make sense of the structure of a story problem, which will be useful when students solve story problems and write equations in a later activity. The problem does not have numbers, so the focus can remain on making sense of the problem, rather than computing.

### Launch

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

### Activity

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

### Student Facing

¿Qué observas?
¿Qué te preguntas?

En el acuario hay algunos peces.
Algunos de los peces son rojos y algunos son azules.

### Activity Synthesis

• “¿Dónde se podrían incluir números en este problema-historia?” // “Where might numbers fit into this story problem?” (To tell the number of red fish and the number of blue fish. To tell how many fish there are in all.)

## Activity 1: Tres lecturas: Los peces de Kiran (15 minutes)

### Narrative

The purpose of this activity is to reintroduce students to Put Together, Total Unknown story problems. In this type of problem, there is no action, so students must recognize the addends must be joined to make up the total. Students were introduced to this type of story problem in kindergarten and solved within 10 using objects or drawings. Students also solved Put Together, Total Unknown problems in Unit 1 in the context of data.

Students begin the activity by looking at the problem displayed, rather than in their books. The three reads routine gives students an opportunity to make sense of the problem before looking for a solution. Because there is no action in a put together problem, students identify the important quantities and think about how they might represent them before they solve the problem (MP1). At the end of the launch, students open their books and work on the problem. Students solve in any way they choose including using objects, drawings, words, or numbers, and write an equation to match the story problem.

### Required Materials

Materials to Gather

### Launch

• Groups of 2
• Give students access to 10-frames and connecting cubes or two-color counters.

### Activity

• Display only the problem stem, without revealing the question(s).
• “Vamos a leer este problema 3 veces” // “We are going to read this problem 3 times.”
• 1st Read: “Kiran tiene algunos peces en su acuario. Tiene 4 peces rojos y 5 peces azules” // “Kiran has some fish in his fish tank. He has 4 red fish and 5 blue fish.”
• “¿De qué se trata esta historia?” // “What is this story about?”
• 1 minute: partner discussion
• Listen for and clarify any questions about the context.
• 2nd Read: “Kiran tiene algunos peces en su acuario. Tiene 4 peces rojos y 5 peces azules” // “Kiran has some fish in his fish tank. He has 4 red fish and 5 blue fish.”
• “¿Cuáles son todas las cosas de esta historia que podemos contar?” // “What are all the things we can count in this story?” (the number of red fish, the number of blue fish, the total number of fish)
• 30 seconds: quiet think time
• 2 minutes: partner discussion
• Share and record all quantities.
• Reveal the question(s).
• “¿De qué maneras diferentes podemos resolver este problema?” // “What are different ways we can solve this problem?” (I can use red and blue connecting cubes. I can draw the fish and count them.)
• 30 seconds: quiet think time
• 1 minute: partner discussion
• “Resuelvan el problema” // "Solve the problem."
• 3 minutes: independent work time
• “Compartan con su pareja cómo pensaron” // “Share your thinking with your partner.”
• 2 minutes: partner discussion
• Monitor for students who solve in the following ways and can explain their thinking clearly:
• objects or drawings and count all
• objects or drawings and count on
• numbers and count on

### Student Facing

Kiran tiene algunos peces en su acuario.
Tiene 4 peces rojos y 5 peces azules.
¿Cuántos peces tiene en total?
Muestra cómo pensaste. Usa dibujos, números o palabras.

Ecuación: ________________________________

### Activity Synthesis

• Invite previously identified students to share in sequence above.
• After each student shares, “¿Cómo corresponde esta representación al problema-historia?” // “How does this representation match the story problem?”
• Display $$4+5=\boxed{9}$$.
• “¿Dónde ven las partes de esta ecuación en esta representación?, ¿y en el problema-historia?” // "Where do you see the parts of this equation in this representation? The story problem?” (4 means the 4 red fish, 5 is the blue fish, 9 is how many he has altogether.)

## Activity 2: Las mascotas de Tyler y Clare (10 minutes)

### Narrative

The purpose of this activity is for students to consider two different equations that represent the same story problem. Put Together, Result Unknown problems help students make sense of the commutative property because the two parts can be combined in different orders. This property, as well as the associative property, is referred to as “add in any order” to students. Students contextualize the problem and see that each number represents a specific object’s quantity, no matter which order it is presented, and connect these quantities to written symbols (MP2). Students will work more with the “add in any order” property in future lessons.

Representation: Access for Perception. Students may benefit from hearing the instructions read aloud more than once.
Supports accessibility for: Language, Attention

### Required Materials

Materials to Gather

### Launch

• Groups of 2
• Give students access to 10-frames and connecting cubes or two-color counters.
• “Acabamos de resolver un problema sobre peces mascota. ¿Qué más saben sobre las mascotas?” // “We just solved a problem about pet fish. What else do you know about pets?”
• 30 seconds: quiet think time
• 1 minute: partner discussion
• If needed ask, “¿Qué tipos de mascotas hay?” // “What kinds of pets are there?”

### Activity

• 3 minutes: independent work time
• 2 minutes: partner discussion
• Monitor for a student who uses objects or drawings to show that each equation matches the story.

### Student Facing

Tyler y Clare quieren saber cuántas mascotas tienen juntos.
Tyler tiene 2 tortugas.
Clare tiene 4 perros.

Tyler escribió la ecuación $$4 + 2= \boxed{6}$$.
Clare escribió la ecuación $$2 + 4 = \boxed{6}$$.

¿Las dos ecuaciones corresponden a la historia?
¿Por qué sí o por qué no?
Muestra cómo pensaste. Usa dibujos, números o palabras.

### Student Response

If students explain that both equations match the story using only numbers, consider asking:

• “¿Cómo sabes que ambas ecuaciones corresponden a la historia?” // "How do you know that both equations match the story?"
• “¿Cómo podrías usar cubos encajables para mostrar que ambas corresponden?” // "How could you use connecting cubes to show that they both match?"

### Activity Synthesis

• Invite previously identified students to share.
• “¿Cómo nos muestra este trabajo que la ecuación de Tyler corresponde a la historia?” // “How does their work show us that Tyler’s equation matches the story?”
• “¿Cómo nos muestra este trabajo que la ecuación de Clare corresponde a la historia?” // “How does their work show us that Clare’s equation matches the story?”

## Activity 3: Centros: Momento de escoger (15 minutes)

### Narrative

The purpose of this activity is for students to choose from activities that offer practice telling and solving story problems and adding and subtracting within 10.

• Math Stories
• Find the Pair
• What’s Behind My Back

### Required Materials

Materials to Gather

### Required Preparation

• Gather materials from previous centers:
• Math Stories, Stage 4
• Find the Pair, Stage 2
• What's Behind My Back, Stage 2

### Launch

• Groups of 2
• “Ahora van a escoger un centro 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” // “Think about what you would like to do.”
• 30 seconds: quiet think time

### Activity

• Invite students to work at the center of their choice.
• 10 minutes: center work time

### Student Facing

Escoge un centro.

Historias matemáticas

Encuentra la pareja

Qué hay a mis espaldas

### Activity Synthesis

• Display a picture from the Math Stories center or from a picture book.
• “¿Qué historias podemos contar sobre este dibujo?” // “What stories can we tell about this picture?”
• If needed, share a Put Together story with the class.

## Lesson Synthesis

### Lesson Synthesis

Display the story about fish in the tank.

“Hoy vimos dos ecuaciones diferentes que correspondían a la misma historia. ¿Cuáles son las dos ecuaciones que corresponden a esta historia?” // "Today we saw two different equations that matched the same story. What are two equations that match this story?" (4 + 5 = 9 and 5 + 4 = 9)

Use 4 red cubes and 5 blue cubes to show beginning with either one, and adding the other, leads to the same total.