Lesson 2

This warm-up 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 describe the attributes of shapes when comparing them. During the synthesis, ask students to explain the meaning of any terminology they use, especially regarding the use of “same” or “different” sides and corners.

• 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

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

• “¿Cuáles de estas figuras son pentágonos? Expliquen” // “Which of these shapes are pentagons? Explain.” (A, C, and D, because they each have 5 sides and 5 corners.)
• “¿Por qué B no es un pentágono?” // “Why is B not a pentagon?” (It isn’t closed. It only has 4 corners.)
  • Consider asking: “¿Cuántos lados tiene? ¿Cuántas esquinas tiene?” // “How many sides does it have? How many corners?”

The purpose of this activity is for students to draw quadrilaterals, pentagons, and hexagons and compare the attributes of different shapes that have the same number of sides. They continue to notice that shapes in these categories have the same number of sides and number of corners. They may describe differences in shapes that are in the same category based on the length of the sides and their orientation. They may also use informal language to describe differences in the corners of each shape (for example, square corners or “sharp” corners). Students learn to describe and measure angles formally in grade 4.

• Groups of 2

• “Hoy van a dibujar y a comparar figuras” // “Today you are going to draw and compare shapes.”
• 5 minutes: independent work time
• Monitor for:
  • examples of shapes that have different side lengths, angles, and orientations to share in synthesis 
  • non-examples of quadrilaterals, pentagons, or hexagons
• “Comparen sus figuras con las de su compañero. Encuentren algo en lo que sus figuras se parezcan y algo en lo que sean diferentes” // “Compare your shapes with your partner’s shapes. Find one way your shapes are the same and one way they are different.”
• 4 minutes: partner discussion

If students draw shapes with a number of sides other than the number of sides that define the named shape, consider asking:

• “¿Cómo sabes que esto es un ______ (cuadrilátero, pentágono o hexágono)?” // “How do you know this is a ______ (quadrilateral, pentagon or hexagon)?”
• “¿Cómo podrías usar la figura que hiciste como ayuda para dibujar otro ______ (cuadrilátero, pentágono o hexágono)?” // “How could you use the completed shape to help you draw another ______ (quadrilateral, pentagon or hexagon)?”

• Display 2–3 previously identified student examples of each shape.
• “¿En qué son diferentes estas figuras?” // “What are the ways these shapes are different?” (different side lengths, different corners)
• If time, display non-examples of quadrilaterals, pentagons, or hexagons that students drew or display some examples, such as:

• “¿Alguna de estas figuras es un cuadrilátero, un pentágono o un hexágono? ¿Por qué sí o por qué no?” // “Would any of these shapes be a quadrilateral, pentagon, or hexagon? Why or why not?” (Sample response: No. The one on the far left has 4 sides and only 3 corners, so it’s not a quadrilateral.)

The purpose of this activity is for students to draw shapes that have a given number of sides or corners. Students then compare shapes based on their number of sides and corners.

• Groups of 2

• “Clare, Andre y Han dibujaron figuras. Usen las pistas para ver si pueden descubrir cuáles son las figuras de cada estudiante. Luego, dibujen una figura diferente a partir de las pistas” // “Clare, Andre, and Han drew shapes. Using the clues, see if you can figure out which shapes might belong to each student. Then draw a different shape based on the clues.”
• 7 minutes: independent work time
• Monitor for examples of Han’s shape that have different numbers of sides, number of corners, side lengths, and angles to share in the synthesis.
• “Comparen las figuras que dibujaron con las figuras de su compañero” // “Compare the shapes you drew with your partner’s shapes.”
• 5 minutes: partner discussion

If students circle only one shape or draw a shape with a number of sides or corners not meeting the criteria, consider asking:

• “¿Cómo sabes que esta figura puede ser la figura de _____ (Clare o Andre)?” // “How do you know this shape could be _____ (Clare’s or Andre’s) shape?”
• “¿Algunas otras figuras pueden ser la figura de _____ (Clare o Andre)?” // “Are there any other shapes that could be _____ (Clare’s or Andre’s) shape?”
• “¿Cómo puedes cambiar tu figura para que tenga _____ (menos de 5 lados, 4 esquinas o más de 4 esquinas)?” // “How can you change your shape so it has _____ (fewer than 5 sides, 4 corners, or more than 4 corners)?”

• Display 2–3 previously identified student examples for Han’s shape.
• “¿En qué son diferentes estas figuras?” // “How are these shapes different?” (different side lengths, different numbers of sides and corners)
• “¿Cualquiera de estas figuras puede ser la figura de Han? Expliquen” // “Could each of these shapes be Han’s shape? Explain.” (Andre's shape has 4 sides and corners, so it could be any shape that has more than 4 sides and 4 corners. We could draw different shapes as long as they have more than 4 sides and 4 corners.)