# Lesson 5

Ordenemos números del 1 al 20 (optional)

## Warm-up: Conteo grupal: Contemos hacia atrás (10 minutes)

### Narrative

The purpose of this warm-up is for students to practice counting backward from 10 and 20. By counting backward from 10 to 1, students develop fluency with the count sequence to 10, which will be helpful later in this lesson when order numbers 1–20 and find one more and one less than a given number. As students count backward, point to the numbers posted so that students can follow along.

### Launch

• “Empecemos en 10 y contemos hacia atrás hasta 1” // “Let’s start at 10 and count backward to 1.”
• Record as students count.

### Activity

• Repeat 3–4 times.
• “Empecemos en 20 y contemos hacia atrás hasta 1” // “Let’s start at 20 and count backward to 1.”
• Record as students count.
• Repeat 2–3 times.

### Activity Synthesis

• “Si empezamos en 17 y contamos hacia atrás hasta 1, ¿qué número decimos después del 16?” // “If we start at 17 and count backward to 1, what number would we say after 16?”
• “Si empezamos en 11 y contamos hacia atrás hasta 1, ¿qué número decimos después del 11?” // “If we start at 11 and count backward to 1, what number would we say after 11?”

## Activity 1: Ordenemos números (10 minutes)

### Narrative

The purpose of this activity is for students to put numbers 1–20 in order.

MLR8 Discussion Supports. Invite each group to chorally read numbers 1–20 in order once the group agrees on the order. Listen for and clarify questions.

### Required Materials

Materials to Copy

• Number Cards 1-20

### Required Preparation

• Create a set of cards from the blackline master for each group of 4.

### Launch

• Groups of 4
• Give each group of students a set of number cards, not in sequence.

### Activity

• “Con su grupo, ordenen los números del 1 al 20” // “Work with your group to put the numbers in order from 1 to 20.”
• 3 minutes: small-group work time
• “Cuando su grupo esté de acuerdo en que los números están en el orden correcto, escriban los números del 1 al 20 en orden” // “Once your group agrees that the numbers are in the correct order, write the numbers in order from 1 to 20.”
• 3 minutes: independent work time

### Student Facing

Escribe los números en orden.

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### Activity Synthesis

• “¿Cómo decidieron el orden de los números?” // “How did you decide the order of the numbers?”
• Display numbers 1–12 in order.
• “Clare está ordenando los números. ¿Qué le dirían para ayudarle a encontrar el número que viene después?” // “Clare is putting the numbers in order. What would you say to her to help her find the number that comes next?” (Look for 13 because it comes after 12. Look for the number that has a 3 because the last number has a 2.)

## Activity 2: Pistas sobre números (15 minutes)

### Narrative

The purpose of this activity is for students to use their knowledge of the number sequence to find the number that matches clues with one more and one less. Numbers 1–20 are displayed around the room. The numbers may be displayed in order, or the sequence of numbers can be mixed up for more of a challenge. The cards with number clues are included as a blackline master; one example is included in the student-facing task statement. Consider developing a signal, such as ringing a bell, so that students know when to move around the classroom. In the activity synthesis, students consider why there can be different clues that match a given number.

Engagement: Internalize Self-Regulation. Provide students an opportunity to self-assess and reflect on the number clue and if that number clue matches the number they will stand by. For example, students can choral count together to check that the number 9 is 1 less than 10.
Supports accessibility for: Memory, Conceptual Processing

### Required Materials

Materials to Copy

• Number Clues, Spanish

### Required Preparation

• Each group of 2 needs one card from the blackline master.
• Display large numbers 1 to 20 around the room. The numbers may be displayed in order, or the sequence of numbers can be mixed up for more of a challenge.

### Launch

• Groups of 2
• Display number cards 0–20 around the room, in order or mixed up.
• Give each group of students a card.
• “En su tarjeta hay algunas pistas. Cada pista dice ‘1 más que _____’ o ‘1 menos que _____’” // “On your card there are some clues. Each clue says ‘1 more than _____’ or ‘1 less than _____.’”
• “Miren la primera pista. Con su pareja, decidan a cuál número le corresponde la pista. Después, busquen en el salón y encuentren ese número. Cuando les haga una señal, caminen hacia ese número” // “Look at your first clue. Decide with your partner which number matches the clue. Then look around the room and find that number. When I give the signal, walk over to that number.”

### Activity

• 2 minutes: partner work time
• “Discutan con las otras personas que caminaron hacia su número. ¿Tienen la misma pista? ¿Todos están en el número correcto? ¿Cómo lo saben?” // “Discuss with the other people at your number. Did you have the same clue? Are you all at the correct number? How do you know?”
• 2 minutes: small-group work time
• Repeat the steps with the rest of the clues.
• During the final round, monitor for a group that notices there are 2 different clues that match the number and discuss why they both match.

### Activity Synthesis

• Invite previously identified students to share what they noticed during the last round of number clues.
• “‘1 más que 15’ y ‘1 menos que 17’ son pistas para el 16” // “‘1 more than 15’ and ‘1 less than 17’ are both clues to 16.”
• “Mencionen dos pistas diferentes que le podrían corresponder al número 12” // “What are two different clues that could match the number 12?”

## 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 number and shape concepts. Students choose from 5 centers introduced in previous units. Students can choose to work at any stage of the centers.
• Less, Same, More
• Math Fingers
• Tower Build
• Math Stories
• Which One

### Required Materials

Materials to Gather

### Required Preparation

• Gather materials from:
• Less, Same, More
• Math Fingers
• Tower Build
• Math Stories
• Which One

### Launch

• Groups of 2
• “Hoy vamos a escoger centros de los que ya conocemos” // “Today we are going to choose from centers we have already learned.”
• 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.

Menos, lo mismo, más

Dedos matemáticos

Construcción de torres

Historias matemáticas

¿Cuál es?

### Activity Synthesis

• “En la clase de matemáticas, es importante explicar cómo pensaron. Describan un momento en el que hayan podido explicarle sus ideas a otras personas de su clase” // “In math class, it’s important to be able to explain your thinking. Describe a time when you were able to explain your ideas to other people in your class.”

## Lesson Synthesis

### Lesson Synthesis

Display number cards 1–20 in order, but with 16 missing.

“Yo ordené mis números del 1 al 20, pero uno de mis números desapareció. ¿Cuál número hace falta y cómo lo saben?” // “I put my numbers in order from 1 to 20, but one of my numbers went missing. Which number is missing and how do you know?” (16 is missing. The missing number comes after 15. The missing number is 1 more than 15. The missing number is 1 less than 17.)

## Student Section Summary

### Student Facing

En esta sección, contamos y comparamos grupos de objetos.

Hay 14 fichas y 12 cubos. Hay menos cubos.

También nos ayudó lo que sabemos sobre cómo contar para descifrar 1 más y 1 menos.

1, 2, 3, 4, 5, 6, 7, 8

8 es 1 más que 7.

Había 10 personas en el bus. Después 1 persona bajó del bus. ¿Cuántas personas hay ahora en el bus?

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Cuando contamos, el 9 está antes que el 10, así que 9 es 1 menos que 10.