# Lesson 1

Comparemos longitudes

## Warm-up: Observa y pregúntate: Lápices (10 minutes)

### Narrative

The purpose of this warm-up is to elicit the idea that it is important to line up the endpoints of objects in order to compare their length, which will be useful when students compare lengths in a later activity. While students may notice and wonder many things about these images, comparing the length using is the important discussion point.

### Launch

• Groups of 2
• Display the image.
• “¿Qué observan? ¿Qué se preguntan?” // “What do you notice? What do you wonder?”
• 1 minute: quiet think time

### Activity

• “Discutan con su compañero lo que pensaron” // “Discuss your thinking with your partner.”
• 1 minute: partner discussion
• Share and record responses.

### Student Facing

¿Qué observas?
¿Qué te preguntas?

### Activity Synthesis

• “¿Cuál lápiz creen que es el más largo? ¿Por qué?” // “Which pencil do you think is the longest? Why?” (It looks like they are all the same, but it’s hard to know.)

## Activity 1: ¿Es más largo o más corto? (15 minutes)

### Narrative

The purpose of this activity is for students to compare the length of two objects directly. In the launch, students share statements comparing a pencil and a crayon. Students may share different observations (about color or other attributes) before focusing on the attribute of length. Students individually choose two objects, compare them and describe their lengths using complete sentences (for example, the pencil is longer than the crayon). It may be helpful to organize the materials in bags or buckets because they will be used in other activities. In the lesson synthesis, students discuss why it is important to line objects up at their endpoints when comparing their length and they make comparisons using precise language (MP3, MP6).

MLR2 Collect and Display. Circulate, listen for and collect the language students use as they compare the lengths of objects. On a visible display, record words and phrases such as: longer than, shorter than, long, line up. Invite students to borrow language from the display as needed, and update it throughout the lesson.
Representation: Access for Perception. Provide appropriate reading accommodations and supports to ensure student access to written directions and written questions.
Supports accessibility for: Language; Social-Emotional Functioning

### Required Materials

Materials to Gather

### Required Preparation

• Each group of 4 needs 10-12 objects to measure (thin classroom objects like pencils, crayons, paper clips, toothpicks, markers) including connecting cube towers of 3, 5, and 8.

### Launch

• Groups of 4
• Give each group 10–12 objects.
• Display a pencil and a crayon.
• “¿Qué afirmación de comparación pueden hacer sobre el lápiz y el crayón?” // “What comparison statement can you make about the pencil and the crayon?” (The pencil is longer than the crayon because I put them side by side. The crayon is shorter than the pencil. They are different colors. The pencil is made of wood and the crayon is wax.)
• 30 seconds: quiet think time
• 1 minute: partner discussion
• Share responses.
• If needed, “Cuando comparamos la longitud de dos objetos, podemos hacer una afirmación sobre cuál objeto es más largo o más corto. El lápiz es más largo que el crayón. ¿Qué otra afirmación podemos hacer?” // “When we compare the length of two objects, we can make a statement about which object is longer or shorter. The pencil is longer than the crayon. What other statement can we make?” (The crayon is shorter than the pencil.)

### Activity

• “Compartan con un compañero lo que pensaron sobre las primeras dos preguntas. Después de eso, dibujen o escriban sus respuestas” // “For the first two questions, share your thinking with a partner. After that, you will draw or write down your answers.”
• 10 minutes: group work time
• Monitor for students who line up the endpoints to compare the length.

### Student Facing

Comparte con tu compañero cómo pensaste.
• Escoge 2 objetos y compara sus longitudes.
• Escoge 2 objetos diferentes y compara sus longitudes.
Escribe tus respuestas.

1. Escoge un objeto con el que podrías escribir y encuentra la torre de 3 cubos encajables.

¿Cuál es más largo?

Dibuja los 2 objetos para mostrar cuál es más largo.

2. Escoge otro objeto y encuentra la torre de 8 cubos encajables.

¿Cuál es más corto?

Dibuja los dos objetos para mostrar cuál es más corto.

3. Encuentra un objeto de la colección que sea más corto que tu pie.

Completa el espacio en blanco.

El ________________________________ es más corto que mi pie.

4. Encuentra un objeto de la colección que sea más largo que tu dedo índice.

Completa el espacio en blanco.

El ________________________________ es más largo que mi dedo índice.

### Activity Synthesis

• Invite previously identified students to show how they lined up objects to compare them.
• “¿Qué pasaría si los objetos no estuvieran alineados?” // “What would happen if the objects were not lined up?” (One might look longer even though it wasn’t.)
• “¿Qué afirmación podemos hacer para comparar la longitud de ______ y ______? Usen las frases ‘más largo que’ y ‘más corto que’” // “What statement can we make to compare the length of _____ and _____? Use the phrases ‘longer than’ and ‘shorter than.’” (The ___ is longer than the ___. The ____ is shorter than the ____.)

## Activity 2: Ordenemos objetos (10 minutes)

### Narrative

The purpose of this activity is for students to order three objects by length. Students line up objects from shortest to longest and longest to shortest. Students need to attend to the language in the question to know which way to order the objects. The language and reasoning students use in this activity helps prepare them to compare the length of objects indirectly in future lessons.

### Required Preparation

• Each group of 4 needs the collection of objects from the previous activity.

### Launch

• Groups of 4
• Give each group 10–12 objects.

### Activity

• 5 minutes: small-group work
• Monitor for students who line up the endpoints of the objects.

### Student Facing

1. Toma 3 objetos.

Con tu pareja, ordena los objetos del más corto al más largo.

Traza o dibuja tus objetos.

2. Toma otros 3 objetos.

Con tu pareja, ordena los objetos del más largo al más corto.

Escribe los nombres de los objetos en orden del más largo al más corto.

### Student Response

If students appear to order their objects correctly without lining them up, consider asking:

• “¿Cómo ordenaste tus objetos ____ (del más corto al más largo o del más largo al más corto)?” // “How did you order your objects from ___ (shortest to longest or longest to shortest)?”
• “¿Cómo puedes mostrarle a alguien que tus objetos están ordenados correctamente?” // “How could you prove to someone that your objects are ordered correctly?”

### Activity Synthesis

• Invite previously identified students to demonstrate how they ordered three objects from shortest to longest.
• Display the three objects with the endpoints lined up so all students can see.
• “¿Qué afirmaciones pueden hacer para comparar la longitud de sus objetos?” // “What statements can you make to compare the length of their objects?” (The ___ is longer than the ___ and ___.)
• As time permits, repeat by inviting a previously identified students to demonstrate how they ordered three objects from longest to shortest.

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

### Narrative

The purpose of this activity is for students to choose from activities that offer practice working with two-digit numbers. Students choose from any stage of previously introduced centers.

• Target Numbers

• Five in a Row

• Get Your Numbers in Order

### Required Materials

Materials to Gather

### Required Preparation

• Gather materials from:
• Target Numbers, Stages 1–3
• Five in a Row, Stages 1–6
• Get Your Numbers in Order, Stage 1

### 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.

Números objetivo

Cinco en línea

Ordena tus números

### Activity Synthesis

• Display numbers 2, 1, and 6.

• “Mai está jugando ‘Números objetivo’. Su última suma fue 78. Estos son los números que sacó en su última ronda. ¿Cuál número debería escoger como sus decenas y cuál debería escoger como sus unidades para acercarse lo que más pueda a 95? ¿Por qué?” // “Mai is playing Target Numbers. Her last sum was 78. These are the numbers she rolled on her last round. Which number should she choose as her tens and which should she choose as her ones in order to get as close to 95 as possible? Why?”

## Lesson Synthesis

### Lesson Synthesis

“Hoy comparamos la longitud de varios objetos. También ordenamos objetos del más corto al más largo o del más largo al más corto. Si sacamos seis objetos de nuestra colección, ¿qué podemos hacer para ordenarlos por longitud? ¿Y si sacamos cien objetos?” // “Today we compared the length of objects and put objects in order from shortest to longest or longest to shortest. If we pulled six objects from our collection, what could we do to order them by length? What if we pulled one hundred objects?” (We would need to line them up at their endpoints.)