# Lesson 9

Resolvamos problemas-historia

## Warm-up: Cuántos ves: Suma de dedos (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 image.
• 30 seconds: quiet think time

### Activity

• Display image.
• “Discutan con su pareja cómo pensaron” // “Discuss your thinking with your partner.”
• 1 minute: partner discussion
• Record responses.
• Repeat for each image.

### Student Facing

¿Cuántos dedos ves?
¿Cómo lo sabes?, ¿qué ves?

### Activity Synthesis

• Display the image with four fingers held up.
• “¿Cuántos dedos hay en cada mano?” // “How many fingers are on each hand?” (2 fingers)
• “¿Cuántos dedos hay en total?” // “How many fingers are there together?” (4 fingers)
• “2 y 2 es 4. También podemos escribir eso como $$2 + 2$$” // “2 and 2 is 4. We can also write that as $$2 + 2$$.”

## Activity 1: Marcadores en la escuela (10 minutes)

### Narrative

The purpose of this activity is for students to represent and solve an Add To, Result Unknown story problem. In the synthesis, students explain how they represented the story with different objects (MP2).

### Required Materials

Materials to Gather

### Launch

• Groups of 2
• “Cuéntenle a su compañero lo que ocurrió en la historia” // “Tell your partner what happened in the story.”
• 30 seconds: quiet think time
• 1 minute: partner discussion
• Monitor for students who accurately retell the story. Choose at least one student to share with the class.
• “Muestren cómo pensaron. Usen dibujos, números, palabras u objetos” // “Show your thinking using drawings, numbers, words, or objects.”

### Activity

• 2 minutes: quiet work time
• 2 minutes: partner discussion
• Monitor for a student who uses markers to solve the problem. Monitor for a student who uses counters or connecting cubes to solve the problem.

### Student Facing

Había 4 marcadores en la escuela.

Elena trajo 3 marcadores más a la escuela.

¿Cuántos marcadores hay ahora en la escuela?

### Student Response

If students take out more or fewer than 7 markers or counters, consider asking:

• “¿Puedes usar tus marcadores/fichas para contarme lo que ocurrió en la historia?” // “Can you use your markers/counters to tell me what happened in the story?”
• “Había 4 marcadores en la escuela. ¿Cuáles marcadores/fichas muestran los 4 marcadores que estaban en la escuela? ¿Cuáles marcadores/fichas muestran los 3 marcadores que Elena trajo a la escuela?” // “There were 4 markers at school. Which markers/counters show the 4 markers that were at school? Which markers/counters show the 3 more markers that Elena brought to school?”

### Activity Synthesis

• Invite a student who used markers to share.
• “¿Cómo muestran los marcadores lo que ocurrió en la historia?” // “How do the markers show what happened in the story?”
• Invite a student who used counters or connecting cubes to share.
• “¿Cómo muestran las fichas lo que ocurrió en la historia?” // “How do the counters show what happened in the story?” (Those counters show the markers that were at school. Those counters show the markers that Elena brought to school.)
• “Había 4 marcadores y Elena trajo 3 marcadores más. 4 marcadores y 3 marcadores es 7 marcadores. Podemos escribir eso como ‘4 y 3’ o ‘$$4 + 3$$’” // “There were 4 markers and Elena brought 3 more markers. 4 markers and 3 markers is 7 markers. We can write that as ‘4 and 3’ or ‘$$4 + 3$$’.”

## Activity 2: Balones en el recreo (10 minutes)

### Narrative

The purpose of this activity is for students to interpret how a drawing represents a story problem (MP2). Students solve a Take From, Result Unknown story problem. Because balls are the objects in the story problem, it may be easier to relate the circles in a picture to the balls in the story. Students are introduced to the number 0 in the activity synthesis.

MLR8 Discussion Supports. Synthesis: Pair verbal descriptions with gestures by pointing to the number 0 to clarify the meaning of similar terms or phrases such as “ninguno” // “none” or “no quedan balones” // “there are no balls left.”
Representation: Develop Language and Symbols. Synthesis: Support student understanding of the situation by acting out the removing of the balls Diego took inside. In addition to crossing out the circles, students may also benefit from seeing the 5 counters and having 5 of them removed.
Supports accessibility for: Conceptual Processing

### Launch

• Groups of 2
• “Cuéntenle a su compañero lo que ocurrió en la historia” // “Tell your partner what happened in the story.”
• 30 seconds: quiet think time
• 1 minute: partner discussion
• Monitor for students who accurately retell the story. Choose at least one student to share with the class.
• “Muestren cómo pensaron. Usen dibujos, números, palabras u objetos” // “Show your thinking using drawings, numbers, words, or objects.”

### Activity

• 2 minutes: quiet work time
• 2 minutes: partner discussion

### Student Facing

Había 5 balones en el patio de recreo.

Diego llevó 5 de los balones para adentro.

¿Cuántos balones hay en el patio de recreo ahora?

### Activity Synthesis

• Draw 5 circles in a line with 5 of them crossed out, as pictured:
• “Lin hizo este dibujo. ¿Cómo muestra este dibujo lo que ocurrió en la historia?” // “Lin drew this picture. How does this picture show what happened in the story?”
• If needed, ask “¿En qué parte del dibujo ven los 5 balones que están en el patio de recreo?” // “Where do you see 5 balls that are on the playground in the picture?” and “¿Por qué 5 de los círculos están tachados?” // “Why are 5 of the circles crossed out?”
• “¿Cuántos balones hay en el patio de recreo ahora?” // “How many balls are on the playground now?” (None, zero.)
• “No quedan balones en el patio de recreo. Hay 0.” // “There are no balls left on the playground. There are 0.”
• Demonstrate writing the number 0.
• “Había 5 balones en el patio de recreo y Diego llevó 5 de los balones para adentro. Podemos escribir eso como ‘5 quitando 5’ o ‘$$5 - 5$$’. 5 quitando 5 es 0” // “There were 5 balls on the playground and Diego brought 5 of the balls inside. We can write that as ‘5 take away 5’ or ‘$$5 - 5$$’. 5 take away 5 is 0.”

## Activity 3: Conozcamos “Dedos matemáticos: Suma 2 manos” (25 minutes)

### Narrative

The purpose of this activity is for students to learn stage 3 of the Math Fingers center. Students each hold up some fingers on one hand and work with their partner to figure out how many fingers they are holding up together. Students color the fingers on the recording sheet and write a number to show how many fingers there are altogether. The recording sheet can be laminated or in a sheet protector so it can be used multiple times by students.

After they participate in the center, students choose from any stage of previously introduced centers.

• Math Stories
• Subtraction Towers
• 5-frames
• Build Shapes
• Counting Collections

### Required Materials

Materials to Gather

Materials to Copy

• Math Fingers Stage 3 Recording Sheet

### Required Preparation

• Gather materials from:
• Math Stories, Stages 1 and 2
• Subtraction Towers, Stage 1
• 5-frames, Stages 1 and 2
• Build Shapes, Stages 1 and 2
• Counting Collections, Stage 1

### Launch

• Groups of 2
• Give each student a recording sheet.
• “Vamos a aprender una nueva forma de trabajar en el centro ‘Dedos matemáticos’. Se llama ‘Dedos matemáticos: Suma 2 manos’” // “We are going to learn a new way to do the Math Fingers center. It is called Math Fingers, Add 2 Hands.”
• “Mi compañero y yo vamos a levantar, cada uno, algunos dedos de 1 mano” // “My partner and I will each hold up some fingers on 1 hand.”
• Hold up 3 fingers on 1 hand. Choose a student to hold up 2 fingers on 1 hand.
• “Ahora tenemos que descubrir cuántos dedos estamos levantando en total. ¿Cómo podemos descifrar esto?” // “Now we have to figure out how many fingers we are holding up altogether. How can we figure it out?” (You can count the fingers. You can put your fingers together. You can look and see that it’s 3 and 2, which is 5.)
• Display math fingers recording sheet.
• “Ahora cada uno de nosotros debe llenar su hoja de registro. Primero, coloreamos los dedos para mostrar cuáles dedos estábamos levantando. Luego, escribimos un número para mostrar cuántos dedos levantamos de cada mano” // “Now we each need to fill out our recording sheet. First we color the fingers to show which fingers we were holding up. Then we write a number to show how many fingers we held up on each hand.”
• “¿Qué número piensan que escribimos en la parte de abajo de la página?” // “What number do you think we write at the bottom of the page?” (How many fingers you held up altogether.)
• “Es su turno de jugar con su compañero. Escondan 1 mano detrás de su espalda. Cuenten hasta 3. Cuando lleguen a 3, levanten algunos dedos de 1 mano” // “It’s your turn to play with your partner. Put 1 hand behind your back. Count to 3. When it gets to 3, hold up some of your fingers on 1 hand.”

### Activity

• 8 minutes: partner work time
• “Ahora pueden escoger otro centro. También pueden seguir jugando ‘Dedos matemáticos’” // “Now you can choose another center. You can also continue playing Math Fingers.”
• Display the center choices in the student book.
• Invite students to work at the center of their choice.
• 10 minutes: center work time
• If time, invite students to choose another center.

### Student Facing

Escoge un centro.

Dedos matemáticos

Historias matemáticas

Torres para restar

Tableros de 5

Construye figuras

Contar colecciones

### Activity Synthesis

• “Cuando descifraban con su compañero cuántos dedos tenían ambos levantados, ¿hubo algún momento en el que no tuvieron que contar los dedos? ¿Cómo supieron cuántos dedos había?” //  “Was there a time when you didn’t need to count the fingers to figure out how many fingers you and your partner held up together? How did you know how many fingers there were?” (I could just see that I had 2 fingers and my partner had 2 fingers. I know that 2 and 2 is 4. I only had 1 finger up and my partner had 3 fingers up. I know that 3 and 1 more is 4.)

## Lesson Synthesis

### Lesson Synthesis

Reread the story problem from the second activity.

“Tyler usó fichas para mostrar lo que ocurrió en la historia” // “Tyler used counters to show what happened in the story.”
Display 5 counters and demonstrate moving 5 to the side.

“Jada hizo un dibujo para mostrar lo que ocurrió en la historia” // “Jada drew a picture to show what happened in the story.”
Draw and display 5 circles in a line with 5 crossed out.

“¿En qué se parecen las formas en las que ellos mostraron la historia? ¿En qué son diferentes?” // “What is the same about how they showed the story? What is different?”