# Lesson 7

Respondamos preguntas sobre gráficas de barras con escala

## Warm-up: Cuántos ves: Grupos de puntos (10 minutes)

### Narrative

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

When students notice that some of the dots are in equal groups and skip-count to find the total number of dots they are looking for and making use of structure (MP7).

### Launch

• Groups of 2
• “¿Cuántos ven? ¿Cómo lo saben?, ¿qué ven?” // “How many do you see? How you do see them?”
• Flash the image.
• 30 seconds: quiet think time

### Activity

• Display the 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 ves? ¿Cómo lo sabes?, ¿qué ves?

### Activity Synthesis

• “¿Cómo les ayudó pensar en grupos de puntos a encontrar el número total de puntos?” // “How did thinking about groups help you find the total number of dots?” (Some of the dots were in groups and some were not. I used skip-counting to count the groups that were the same size, then added on the rest of the dots.)
• “¿Alguien puede expresar con otras palabras la forma en la que _____ vio los puntos?” // “Who can restate the way _____ saw the dots in different words?”
• “¿Alguien vio los puntos de la misma manera, pero lo explicaría de otra forma?” // “Did anyone see the dots the same way but would explain it differently?”

## Activity 1: Preguntas sobre el momento favorito del año (15 minutes)

### Narrative

The purpose of this activity is for students to use data presented in scaled bar graphs to solve one-step “how many more” and “how many fewer” problems. Students use scaled bar graphs that they created in the previous lesson that contain data about the favorite time of the year. Answering questions about a graph with which they are familiar prepares them for the next task in which they answer questions about a new graph. This activity provides an opportunity for formative assessment of students addition and subtraction methods. In grade 2, students were expected to fluently add and subtract within 100.

### Required Materials

Materials to Gather

### Required Preparation

Students will need their Favorite Time of the Year graphs from the previous lesson.

### Launch

• Groups of 2
• Make sure that students have their Favorite Time of the Year graphs from a previous lesson.
• “Van a usar la gráfica de una lección anterior para responder algunas preguntas sobre los momentos favoritos del año. Tómense un minuto para mirar las preguntas” // “Take a minute to look over the questions you’ll answer using the Favorite Time of the Year graph from a previous lesson.”
• 1 minute: quiet think time

### Activity

• “Respondan las preguntas con su pareja” //“Work with your partner to answer the questions.”
• 7–10 minutes: partner work time
• Monitor for different strategies students use to add or subtract, particularly strategies that use tens and ones.

### Student Facing

Usa tu gráfica sobre los momentos favoritos del año para responder a las preguntas. Muestra cómo pensaste. Usa expresiones o ecuaciones.

1. ¿Cuántos estudiantes están representados en la gráfica?
2. ¿Cuántos estudiantes escogieron primavera u otoño como su momento favorito?
3. ¿Cuántos estudiantes más escogieron verano que invierno?
4. ¿Cuántos estudiantes menos escogieron primavera que otoño?

### Student Response

If students find the sum of the quantities in the compare problems or do not find a value, consider asking:

• “¿De qué se trata este problema?” // “What is this problem about?”
• “¿Cómo usarías las palabras 'más qué' o 'menos que' para describir dos categorías de la gráfica?” // “How would you describe two categories in the graph using the phrase, ‘more than’ or ‘fewer than’”

### Activity Synthesis

• Have students share responses to the last 2 questions.
• “¿En qué se parecen estas preguntas? ¿En qué son diferentes?” // “How are these questions the same? How are they different?” (They both ask about the difference between 2 categories. The first question uses “more” and the second question uses “fewer.”)
• As students share, use this as an opportunity to highlight addition and subtraction strategies in which students use tens and ones.

## Activity 2: Preguntas sobre insectos del jardín (20 minutes)

### Narrative

The purpose of this activity is for students to use data presented in scaled bar graphs to solve one-step “how many more” and “how many fewer” problems. The graph in the previous activity was familiar to students since they had created it in the previous lesson, but the graph used in this activity is new to students. Because the graph has a scale of 10, students need to estimate values that do not show an exact multiple of 10. As a result, answers may vary slightly. Accept all answers that align to reasonable estimates.

MLR8 Discussion Supports. Synthesis: Involve both students in sharing their response with the whole class. While one student speaks, invite the other student to follow along and point to the corresponding parts of the bar graph on the display.
Representation: Internalize Comprehension. Begin by asking, “¿Esta situación les recuerda algo que hayamos visto, leído o hecho antes?” // “Does this situation remind anyone of something we have seen, read, or done before?”
Supports accessibility for: Social-Emotional Functioning

### Launch

• Groups of 2
• “Miren la gráfica de barras con escala y díganle a su pareja una cosa que observen” // “Look at the scaled bar graph and tell your partner one thing you notice.”
• 1 minute: partner discussion

### Activity

• “Con su pareja, completen los primeros cuatro problemas usando los datos de la gráfica de barras” // “Work with your partner to use the data in the bar graph to complete the first four problems.”
• 7–10 minutes: partner work time
• Monitor for different strategies students use to add or subtract, particularly strategies that use tens and ones.
• “Ahora, intercambien con otra pareja las preguntas que escribieron en el cuarto problema y contesten sus preguntas” // “Now, trade the questions you wrote for the fourth question with another group and answer their questions.”
• 2–3 minutes: partner work time

### Student Facing

Se recolectaron datos para saber cuántos insectos de cada tipo había en un jardín. Los datos se muestran en esta gráfica de barras:

Usa la gráfica de barras para contestar las preguntas. Muestra cómo pensaste. Usa expresiones o ecuaciones.

1. ¿Cuántos insectos había en el jardín?
2. ¿Cuántas hormigas más que arañas había en el jardín?
3. ¿Cuántas mariquitas menos que hormigas había?
4. Con tu pareja, escriban 2 preguntas que se puedan hacer sobre los insectos del jardín.
5. Intercambien las preguntas con otra pareja y contéstenlas.

### Student Response

If students find sums for compare problems or do not find a solution, consider asking:

• “Dime cómo empezaste a trabajar en este problema” // "Tell me about how you started this problem?"
• “¿Cómo podrías usar la información de la gráfica para resolver el problema?” // "How could you use the information from the graph to solve the problem?"

### Activity Synthesis

• Have students share responses for the first three problems. Be sure to share a variety of reasonable estimates for the values in each category to make sure students know it’s okay if they don’t know the exact value for sure.
• Have 2–3 groups share a question they wrote and have the whole class solve it. As students share, use this as an opportunity to highlight addition and subtraction strategies in which students use tens and ones.

## Lesson Synthesis

### Lesson Synthesis

Display the bar graph from the last activity in today’s lesson.

“¿Qué estrategias les ayudaron hoy a responder preguntas sobre los datos representados en gráficas de barras?” // “What were some strategies that were helpful today as you answered questions about the data represented in bar graphs?” (I used the bar graph to get the numbers before I added or subtracted. I used the bar graph to find the answers by looking at one of the bars and counting up to the other bar in the problem.)