# Lesson 14

Torres de 10

## Warm-up: ¿Qué sabes sobre el 10? (10 minutes)

### Narrative

The purpose of this What Do You Know About _____ is to invite students to share what they know and how they can represent the number 10.

### Launch

• Display the number.
• “¿Qué saben sobre el 10?” // “What do you know about 10?”
• 1 minute: quiet think time

### Activity

• Record responses.
• “¿Cómo podemos mostrar el número 10?” // “How could we show the number 10?”

### Student Facing

¿Qué sabes sobre el 10?

### Activity Synthesis

• “Díganle a su compañero 2 maneras diferentes en las que podemos formar 10” // “Tell your partner 2 different ways that we can make 10.”

## Activity 1: Conozcamos “Qué hay a mis espaldas: 10 cubos” (15 minutes)

### Narrative

The purpose of this activity is for students to learn stage 2 of the What’s Behind My Back center. Students snap a tower of 10 cubes into two parts and hide one part behind their back. Then, their partner determines how many connecting cubes are hidden. Students may use connecting cubes, 10-frames and counters, fingers, or drawings to figure out how many connecting cubes are hidden. As they choose a strategy, they will be making use of appropriate tools strategically (MP5). Monitor for students who:

• create another tower of 10 connecting cubes, snap it into two pieces to show the cubes that are showing and then count the rest of the cubes to determine how many cubes are hidden
• hold up the same number of fingers as the number of connecting cubes that are showing and count the number of fingers that are down to determine how many connecting cubes are hidden
• place counters on a 10-frame to represent the connecting cubes that are showing and count the empty squares to determine how many connecting cubes are hidden

### Required Materials

Materials to Gather

Materials to Copy

• What's Behind My Back Stage 2 Recording Sheet Kindergarten

### Required Preparation

• Each group of 2 need 20 connecting cubes.

### Launch

• Groups of 2
• Give each group of students 20 connecting cubes. Give each student a recording sheet and access to two-color counters and 10-frames.
• “Vamos a aprender una nueva forma de jugar el centro ‘Qué hay a mis espaldas’” // “We are going to learn a new way to play the What's Behind My Back? center.”
• “Con su compañero, hagan una torre con 10 cubos encajables” // “Work with your partner to make one tower with 10 connecting cubes.”
• 1 minute: partner work time
• “Decidan quién va primero. Separen la torre en dos partes y escondan una de las partes detrás de su espalda. Muéstrenle la otra parte a su compañero” // “Choose who will go first. Snap the tower into two parts and hide one of the parts behind your back. Show your partner the other part.”
• 30 seconds: partner work time
• “Averigüen cuántos cubos están escondidos detrás de la espalda de su compañero” // “Figure out how many cubes are hidden behind your partner’s back.”
• 2 minutes: independent work time
• “Dibujen o coloreen la torre de cubos encajables para mostrar las dos partes en las que se separó la torre. Juntos, completen una ecuación que muestre el número total de cubos encajables de la torre y las dos partes en las que se separó la torre” // “Draw or color the connecting cube tower to show the two parts that the tower snapped into. Work together to fill in an equation to show the total number of connecting cubes in the tower and the two parts that the tower snapped into.”
• 2 minutes: partner work time
• “Por turnos, separen la torre de 10 cubos y escondan una parte” // “Take turns snapping the tower of 10 cubes and hiding one part.”

### Activity

• 8 minutes: partner work time
• Monitor for students who use the methods outlined in the activity narrative.

### Activity Synthesis

• Select previously identified students to share.
• “¿Cómo les ayudó hacer otra torre de 10 cubos a averiguar cuántos cubos estaban escondidos?” // “How did making another tower of 10 cubes help you figure out how many cubes were hidden?”
• “¿Cómo les ayudaron sus dedos a averiguar cuántos cubos estaban escondidos?” // “How did your fingers help you figure out how many cubes were hidden?”
• “¿Cómo les ayudó poner fichas en el tablero de 10 a averiguar cuántos cubos estaban escondidos?” // “How did putting counters on the 10-frame help you figure out how many cubes were hidden?”

## Activity 2: ¿Cuántos cubos están escondidos? (10 minutes)

### Narrative

The purpose of this activity is for students to determine how many are needed to make 10 when added to a given number. This activity is presented as the same context as the first activity, except students are not shown the visual of the cubes. Because the context is connecting cubes, one natural way to determine how many cubes are hidden is to create and snap a tower of 10 cubes. Students may also use their fingers or put counters on a 10-frame. As they choose a strategy, they reason abstractly and quantitatively (MP2) and they may choose to use appropriate tools strategically (MP5).

MLR8 Discussion Supports. Invite students to say each equation aloud. Listen for and clarify any questions about the equations.
Action and Expression: Internalize Executive Functions. Invite students to plan a strategy, including what drawings, numbers, words, or objects they will use to determine how many cubes Han is hiding.
Supports accessibility for: Conceptual Processing, Organization

### Required Materials

Materials to Gather

### Launch

• Groups of 2
• “Muestren cómo pensaron. Usen dibujos, números, palabras u objetos” // “Show your thinking using drawings, numbers, words, or objects.”

### Activity

• 3 minutes: independent work time
• 2 minutes: partner work time
• Monitor for students who build a tower and snap off 4 cubes to figure out how many cubes are missing.
• “Completen una ecuación para mostrar los cubos de Han” // “Fill in an equation to show Han’s cubes.”
• 1 minute: partner work time

### Student Facing

Han tenía una torre de 10 cubos.

Él la separó en 2 partes y escondió 1 parte detrás de su espalda.

Le mostró 4 cubos a su compañero.

¿Cuántos cubos escondió Han detrás de su espalda?

$$10 = \underline{\hspace{1 cm}} + \underline{\hspace{1 cm}}$$

### Student Response

If students are unsure of how to find the missing part, consider asking:

• “¿Puedes usar cubos para mostrar lo que pasó en la historia?” // “Can you use cubes to show what happened in the story?”
• “¿Cómo puedes usar los cubos para averiguar cuántos cubos esconde Han detrás de su espalda?” // “How can you use the cubes to help you figure out how many cubes Han was hiding behind his back?”

### Activity Synthesis

• Invite students who built towers of connecting cubes to show how they figured out how many cubes were hidden.
• Display a 10-frame with 4 red counters and 6 yellow counters. Display a tower of 10 connecting cubes broken into 4 and 6:
• “¿En qué se parece formar 10 con cubos encajables a formar 10 con un tablero de 10?” // “How is making 10 with connecting cubes the same as using a 10-frame?” (I get the same combinations of numbers to make 10. 4 connecting cubes and 6 connecting cubes make 10 just like with counters.)

## Activity 3: Centros: Momento de escoger (20 minutes)

### Narrative

The purpose of this activity is for students to choose from activities that offer practice with counting, adding, composing, and decomposing numbers.

Students choose from any stage of previously introduced centers.

• What’s Behind My Back?
• Math Fingers
• Shake and Spill
• Counting Collections

### Required Materials

Materials to Gather

### Required Preparation

• Gather materials from:
• What's Behind My Back, Stages 1 and 2
• Math Fingers, Stages 1-4
• Shake and Spill, Stages 1-3
• Counting Collections, Stage 1
• Roll and Add, Stages 1 and 2

### Launch

• “Hoy vamos a escoger centros de los que ya conocemos. También pueden seguir jugando ‘Qué hay a mis espaldas’” // “Today we are going to choose from centers we have already learned. You can also continue playing What’s Behind my Back?”
• Display the center choices in the student book.
• “Piensen qué les gustaría hacer primero” // “Think about what you would like to do first.”
• 30 seconds: quiet think time

### Activity

• Invite students to work at the center of their choice.
• 8 minutes: center work time
• “Escojan qué les gustaría hacer ahora” // “Choose what you would like to do next.”
• 8 minutes: center work time

### Student Facing

Escoge un centro.

¿Qué hay a mis espaldas?

Dedos matemáticos

Revuelve y saca

Contar colecciones

Lanza y suma

### Activity Synthesis

• Display a tower of 10 cubes, snapped into 9 cubes and 1 cube.
• “¿Cuáles son las partes que Elena encontró que forman 10?” // “What are the parts that make 10 that Elena found?” (9 and 1)
• “¿Qué ecuación puede escribir Elena?” // “What equation can Elena write?” ($$10 = 9 + 1$$)

## Lesson Synthesis

### Lesson Synthesis

Display a 10-frame with 4 red and 6 yellow counters.

Display 10 connecting cubes snapped into towers of 1 and 9.

Display 10 fingers.

Write $$10 = 7 + 3$$.

“Hemos explorado muchas maneras de formar 10: tableros de 10, dedos, expresiones y ecuaciones, y torres de cubos encajables” // “We have looked at lots of ways to make 10: 10-frames, fingers, expressions and equations, and towers of connecting cubes.”

“¿Cuál es su manera favorita de formar 10? ¿Por qué es su favorita?” // “What is your favorite way to make 10? Why is it your favorite?”

## Student Section Summary

### Student Facing

En esta sección, encontramos muchas maneras diferentes de formar 10. Usamos un tablero de 10 y nuestros dedos para mostrar números y averiguar cuántos más se necesitaban para formar 10.

Hay 4 fichas.
Necesitamos 6 fichas más para formar 10.

Hay 9 dedos.
Necesitamos levantar 1 dedo más para formar 10.

Usamos ecuaciones para mostrar diferentes maneras de formar 10.

$$10 = 4 + 6$$

$$10 = 9 + 1$$