# Lesson 18

Patrones en la suma

## Warm-up: Cuántos ves: Más tableros de 10 dobles (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. This warm-up is similar to the warm-up in the previous lesson. The teacher can notice if the students’ approach to the warm-up is different after the activities in the previous lesson. When students use grouping strategies to visualize the quantities in the $$10 + n$$ structure they come to see that some can be taken from one group and added to the other to make a ten and some more (MP7).

### 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 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

• “¿Qué tienen en común estas imágenes?” // “What do these images have in common?” (You can take some dots from one 10-frame and add them to the other. None of the 10-frames are full.)
• “La primera imagen muestra $$9 + 5$$, pero si pasamos una ficha amarilla al tablero de 10 que está arriba, podemos escribir $$10 + 4$$” // “The first image shows $$9 + 5$$, but if we share one yellow with the top 10-frame we could write $$10 + 4$$.”
• Write $$9 + 5 = 10 + 4$$.
• “¿Qué expresiones podemos escribir para la segunda imagen?” // “What expressions could we write for the second image?” ($$3 + 9 = 2 + 10$$)

## Activity 1: Expresiones que corresponden (10 minutes)

### Narrative

The purpose of this activity is for students to use what they know about making a ten to identify which addition expressions are equivalent to $$10 + n$$ expressions. Students should have access to double 10-frames and connecting cubes or two-color counters.

The Compare Stage 2 Addition Cards will be used again in a later lesson.

### Required Materials

Materials to Gather

Materials to Copy

• Compare Stage 2 Addition Cards to 20

### Required Preparation

• Create a set of Compare Stage 2 Addition Cards to 20 from the blackline master for each group of 3.

### Launch

• Groups of 3
• Give each group a set of cards and access to double 10-frames and connecting cubes or two-color counters.

### Activity

• 8 minutes: small-group work

### Student Facing

1. Saca y deja a la vista todas las tarjetas que tengan expresiones con 10.
2. Mezcla el resto de las tarjetas.
3. Toma una tarjeta.
4. Pon tu tarjeta debajo de la expresión con 10 que tenga el mismo valor que tu tarjeta.

### Activity Synthesis

• “Vamos a hacer un póster y a hacer un recorrido por el salón” // “We are going to create a poster and do a Gallery Walk.”

## Activity 2: Comparar y conectar: Recorrido por el salón (15 minutes)

### Narrative

The purpose of this activity is for students to create a poster to show all the expressions equivalent to their assigned $$10 + n$$ expression. Before the activity, assign each group an expression for which they will make a poster. Then, students get into new groups of three and each group visits three posters. Students consider what patterns they notice between the expressions on the poster. Students may notice there is a relationship between the addends of equivalent expressions. For example, when one addend decreases by 1, the other addend in the sum increases by 1 (MP7).

This activity uses MLR7 Compare and Connect. Advances: Representing, Conversing

Action and Expression: Develop Expression and Communication. Provide students with alternatives to writing their observations on paper: students can share their observations verbally, or through drawings.
Supports accessibility for: Language, Conceptual Processing

### Launch

• Groups of 3
• Give each group tools for creating a visual display.
• Assign each group an expression.

### Activity

MLR7 Compare and Connect

• “Hagan un póster que muestre las expresiones que son iguales a la expresión con 10 que les asigné” // “Create a visual display that shows the expressions equal to the expression with 10 I assigned you.”
• 3 minutes: small group work
• 7 minutes: gallery walk
• During the gallery walk, consider asking:
• “¿Qué observan sobre las expresiones del póster?” // “What do you notice about the expressions on the poster?”
• “¿Qué patrones observan?” // “What patterns do you notice?”
• “¿Los patrones son los mismos en todos los pósteres?” // “Are the patterns the same across all of the posters?”

### Activity Synthesis

• Display posters for $$10 + 1$$, $$10 + 3$$, and $$10 + 5$$.
• “¿Qué patrones observaron cuando vieron los pósteres al recorrer el salón?” // “What patterns did you notice as you went from poster to poster?” (I saw that there was an expression with 9 on every poster. For example, $$10 + 3$$ is equivalent to $$9 + 4$$. This is because I can take 1 from the 4 and give it to the 9.) To amplify student language and illustrate connections, follow along and point to the relevant parts of the displays as students speak.
• Record responses as equations (for example, $$10 + 3 = 9 + 4$$).
• Record $$10 + 3 = 9 + 4$$“¿El mismo patrón está en otros pósteres?” // “Is the same pattern on other posters?” (Yes, it happened on $$10 + 2$$. If I have $$9 + 3$$, I can take one from the 3 and give it to the 9. Then I have $$10 + 1$$.)

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

### Narrative

The purpose of this activity is for students to choose from activities that offer practice adding and subtracting within 10. Students choose from any stage of previously introduced centers.

• Shake and Spill
• Compare
• Number Puzzles

### Required Materials

Materials to Gather

### Required Preparation

• Gather materials from previous centers:
• Shake and Spill, Stages 3–5
• Compare, Stage 1
• Number Puzzles, Stages 1 and 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.

Revuelve y saca

Compara

Acertijos numéricos

### Activity Synthesis

• Display nine red counters and cover five yellow counters with a cup.
• “Estamos jugando con 14 fichas. ¿Cuántas fichas amarillas hay debajo del vaso? ¿Cómo lo saben?” // “We are playing with 14 counters. How many yellow counters are under the cup? How do you know?”

## Lesson Synthesis

### Lesson Synthesis

Display a double 10-frame with eight counters on the top frame and four on the bottom, and  $$8 + 4 = 10 + 3$$.

“Hoy emparejamos expresiones de suma con expresiones con un 10 que tenían igual valor. ¿Esta ecuación es verdadera o falsa? ¿Cómo lo saben?” // “Today we matched addition expressions to equivalent expressions with a 10. Is this equation true or false? How do you know?” (It’s false, because if I move two counters to the top 10-frame then it shows $$10 + 2$$.)