# Lesson 7

Flat and Solid Shapes

## Warm-up: Which One Doesn’t Belong: Flat Shapes (10 minutes)

### Narrative

This warm-up prompts students to carefully analyze and compare attributes of flat shapes. In making comparisons, students have a reason to use language precisely (MP6). The activity also enables the teacher to hear the terminologies students know and how they talk about attributes of shapes.

### Launch

• Groups of 2
• Display image.
• “Pick one that doesn’t belong. Be ready to share why it doesn’t belong.”
• 1 minute: quiet think time

### Activity

• 2-3 minutes: partner discussion
• Share and record responses.

### Student Facing

Which one doesn’t belong?

### Activity Synthesis

• “Let’s find at least one reason why each one doesn’t belong.”

## Activity 1: Create Shapes with Clay (15 minutes)

### Narrative

The purpose of this activity is for students to build and compare flat and solid shapes. Students are not expected to build precise shapes. Using clay to build the shapes helps students feel the difference between flat and solid shapes. The terms “flat” and “solid” are introduced in the activity synthesis. Students may benefit from getting to hold and see the solid shapes up close as they build them.

### Required Materials

Materials to Gather

### Required Preparation

• Each student needs a piece of clay.
• Gather a cone and cylinder to display.

### Launch

• Groups of 2
• Give each student a piece of clay.
• “Use your clay to make a shape that you know.”
• 1 minute: independent work time
• “Share your shape with your partner. How are they the same? How are they different?” (The shapes are different. I made a circle and my partner made a triangle.)
• 30 seconds: quiet think time
• 1 minute: partner discussion
• Share responses.

### Activity

• Display a cylinder.
• “Make this shape with your clay.”
• 2 minutes: independent work time
• Display a cone.
• “Make this shape with your clay.”
• 2 minutes: independent work time
• “Describe the shape that you made to your partner. What does it look like?” (It looks like an ice cream cone. It’s tall. It has a point on the bottom.)
• 30 seconds: quiet think time
• 2 minutes: partner discussion
• Share responses.

### Activity Synthesis

• Display a group of flat shapes and a group of solid shapes that students created.
• “What is different about the shapes that we made first and the rest of the shapes that we made?” (The shapes that we made first are all flat. The other shapes stick up.)
• “The first shapes that we made were flat shapes, like circles and rectangles. Then we built some other shapes. What can we call these shapes?” (solid shapes, big shapes)
• “These shapes are solid shapes.”
• “Use your clay to make a flat shape.”
• “Use your clay to make a solid shape.”

## Activity 2: Sort Flat and Solid Shapes (10 minutes)

### Narrative

The purpose of this activity is for students to identify shapes as flat and solid as they sort shapes into groups. A sorting task gives students opportunities to analyze the structure of the shapes and identify common properties and characteristics (MP7). If the sorting mat provided in the student workbook is too small for students to sort the shapes, consider giving students two pieces of construction paper, or ask students to put the solid shapes on one side of the table and the flat shapes on the other side.

MLR8 Discussion Supports. Invite each partner to identify each shape aloud: Flat shape or solid shape. Encourage students to challenge each other when they disagree.
Action and Expression: Internalize Executive Functions. Invite students to plan a strategy for how they will sort the shapes.
Supports accessibility for: Conceptual Processing, Organization

### Required Materials

Materials to Gather

Materials to Copy

• Flat Shapes Cards K

### Required Preparation

• Each group of 2 needs a set of solid shapes and a set of cards.

### Launch

• Groups of 2
• Give each group of students a set of solid shapes and a set of flat shapes cards.

### Activity

• “Work with your partner to sort the shapes into two groups. Write a number to show how many shapes are in each group.”
• 3 minutes: partner work time
• “Pair up with another group. Show them how you sorted your shapes. Did you sort all of the shapes in the same way?”
• 3 minutes: small-group work time
• “What could you call each group of shapes to show why you put those shapes together?”
• Monitor for a group that sorts by flat shapes and solid shapes.

_______________

_______________

### Student Response

If students identify a pyramid as flat because “it looks like a triangle,” consider asking:
• “What is the same about all of the shapes in this group?”
• Display a pyramid and a triangle next to each other and ask “What do you notice about these shapes? What is different about them?”

### Activity Synthesis

• Invite previously selected students to share the way they sorted the shapes into flat shapes and solid shapes.
• “This group has flat shapes. This group has solid shapes.”
• Display a square.
• “Should this shape go with the flat shapes or the solid shapes? Why?” (It is a flat shape. If we put it on our desk, it doesn’t stick up.)
• Display a cube.
• “Should this shape go with the flat shapes or the solid shapes? Why?” (It is a solid shape. It sticks up and takes up space.)

## Activity 3: Centers: Choice Time (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 any stage of previously introduced centers.

• Counting Collections
• Match Mine
• Shake and Spill

Students will choose from these centers throughout the section. Keep materials from these centers organized to use each day.

### Required Materials

Materials to Gather

### Required Preparation

• Gather materials from:
• Counting Collections, Stage 1
• Match Mine, Stage 1
• Shake and Spill, Stages 1-4

### Launch

• “Today we are going to choose from centers we have already learned.”
• Display the center choices in the student book.
• “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
• “Choose what you would like to do next.”
• 8 minutes: center work time

### Student Facing

Choose a center.

Counting Collections

Match Mine

Shake and Spill

### Activity Synthesis

• Display 4 pattern blocks arranged as pictured.
• “What would you tell your partner about where to put the red trapezoid pattern block?” (It’s under the yellow hexagon and over the blue rhombus.)

## Lesson Synthesis

### Lesson Synthesis

Display a circle and a cylinder.

“How are these shapes the same? How are they different?” (They both have parts that are round. One shape is a circle and the other shape has a circle on the top. One is flat and one is solid.)