# Lesson 1

¿Qué características ves?

## Warm-up: Cuál es diferente: ¿Quién está en el grupo? (10 minutes)

### Narrative

This activity prompts students to compare four shapes. It gives students a reason to use language precisely (MP6). It gives the teacher an opportunity to hear how students use terminology and talk about the characteristics of the items in comparison to one another. During the synthesis, ask students to explain the meaning of any terminology they use, such as sides, corners, quadrilateral, and pentagon.

### Launch

• Groups of 2
• Display the image.
• “Escojan una que sea diferente. Prepárense para compartir por qué es diferente” // “Pick one that doesn’t belong. Be ready to share why it doesn’t belong.”
• 1 minute: quiet think time

### Activity

• “Discutan con su compañero lo que pensaron” // “Discuss your thinking with your partner.”
• 2–3 minutes: partner discussion
• Share and record responses.

### Student Facing

¿Cuál es diferente?

### Activity Synthesis

• “Encontremos al menos una razón por la que cada una es diferente” // “Let’s find at least one reason why each one doesn’t belong.”

## Activity 1: Clasificación de tarjetas: Figuras (35 minutes)

### Narrative

The purpose of this activity is to encourage students to observe attributes of shapes and use them to sort shapes into groups. When students sort the cards, they look for common attributes or structures shared by different shapes (MP7). Students notice that there are multiple ways to categorize the shapes and that a shape may belong to more than one category depending on the attributes used to sort.

In grade 2, students refer to right angles as square corners. Here, students learn to use the terms angle in a shape and right angle in a shape to describe the corners of shapes. Note that the term “angle” here is understood informally and used only in reference to shapes and their geometric attributes (for instance, to distinguish rhombuses from squares). Students will not learn the formal definition of an angle—a figure formed by two rays that share an endpoint—or that it is a measurable attribute until grade 4.

When students consider the language they use and revise it to describe a shape in detail or with more specificity, they attend to precision (MP6).

The cards in this activity will be used again in centers.

MLR2 Collect and Display. Collect the language students use to sort the cards into categories. Display words and phrases such as: “lados iguales”, “longitudes iguales”, “esquinas”, “diagonal”, “recto”, “curvo”, “inclinado” y “sombreado” // “equal sides,” “equal lengths,” “corners,” “diagonal,” “straight,” “curved,” “slanted,” and “shaded.” During the synthesis, invite students to suggest ways to update the display: “¿Qué otras palabras o frases deberíamos incluir?” // “What are some other words or phrases we should include?” etc. Invite students to borrow language from the display as needed.
Representation: Develop Language and Symbols. Synthesis: Maintain a visible display to record new vocabulary. Invite students to suggest details (words or pictures) that will help them remember the meaning of angle and right angle.
Supports accessibility for: Memory

### Required Materials

Materials to Copy

### Required Preparation

• Create a set of cards from the blackline master for each group of 2.

### Launch

• Groups of 2
• Distribute one set of pre-cut cards to each group of students.
• “¿Qué tipos de palabras usamos para describir figuras?” // “What kinds of words do we use to describe shapes?” (sides, corners, flat, curved, diagonal)

### Activity

• “En esta actividad van a clasificar algunas tarjetas en categorías de una manera que tenga sentido para ustedes. Invéntense las categorías con su compañero y después clasifiquen las figuras” // “In this activity, you will sort some cards into categories in a way that makes sense to you. Work with your partner to come up with categories and then sort the shapes.”
• 8 minutes: partner work time
• Pause for a discussion. Invite groups to share their sorted shapes without naming the categories.
• As each group shares, ask the class to guess the categories and whether others have sorted the same way.
• Record and display the attributes each group used to categorize the shapes (for example: number of sides, length of sides, shading, types of corners).
• “Ahora, por turnos, van a clasificar sus figuras en categorías secretas. Su compañero va a adivinar cómo clasificaron sus figuras en esas categorías” // “Now, you’ll take turns sorting your shapes in a secret way and see if your partner can guess how you sorted your shapes into categories.”
• 10 minutes: partner work time

### Student Facing

Tú profesor te va a dar varias tarjetas que muestran figuras.

1. Clasifica las tarjetas en categorías con tu compañero. Prepárate para explicar tus categorías.
2. Por turnos, con tu compañero, clasifica las tarjetas en dos categorías nuevas. No le digas a tu compañero cómo las clasificaste. Después, tu compañero va a adivinar cómo clasificaste las figuras.

### Activity Synthesis

• Invite groups to share any new categories that came up during their partner work time. Record any additional attributes used to sort the shapes.
• “¿Qué palabras o frases les ayudaron a describir las figuras?” // “What words or phrases were helpful for describing the shapes?” (four, five, side, corner, length, equal, triangle, square, rectangle, pentagon, hexagon)
• Display card O.
• “La parte de la figura en donde dos lados se encuentran se llama un ángulo de la figura. ¿Cuántos ángulos tiene esta figura?” // “The part of the shape where two sides meet is called an angle in the shape. How many angles does this shape have?” (Shape O has 4 angles.)
• “Esta figura también tiene dos ángulos especiales. Sus lados se unen de una manera que se forma un ángulo recto de la figura. Esta es la manera en la que los lados se unen en un cuadrado y en un rectángulo. ¿Qué otras figuras tienen ángulos rectos?” //  “This shape also has two special angles. Their sides join in a way that forms a right angle in the shape. This is the way the sides join in a square and in rectangles. What other shapes have right angles?” (B, F, M, and S)

## Lesson Synthesis

### Lesson Synthesis

“Hoy clasificamos figuras en categorías teniendo en cuenta sus características. Vimos que una figura podía estar en categorías diferentes, dependiendo de cuál característica usamos” // “Today we sorted shapes into categories based on their attributes. We saw that a shape could belong in different categories depending on which attribute we use.”

Display cards A and S from the first activity.

“Supongamos que un estudiante pone A y S en la misma categoría. ¿Qué característica pudo haber usado para clasificar las figuras?” // “Suppose a student puts A and S in the same category. Which attribute might they have used to sort shapes?” (Length of the sides: A and S have sides with equal length. Size of corners or angles: Both shapes have corners that are the same size. Shading: Neither shape is shaded.)

“Supongamos que otro estudiante pone A y S en categorías diferentes. ¿Qué característica pudo haber usado para clasificar las figuras?” // “Suppose another student puts A and S in different categories. Which attribute might have they used to sort the shapes?” (Right angles: A has none and S has two. Equal sides: All sides of A are equal, but not all sides of S are. Number of sides: A has three, S has five.)