Flat Surfaces as Two- Dimensional Shapes Unit of Study: 3-Dimensional Shapes Global Concept Guide: 3 of 3

Content Development  It is important to help students understand the relationship between three-dimensional shapes and their two-dimensional flat surfaces.  Students do not always make the connection that 2-dimensional shapes when put together make 3-dimensional shapes.  It is important to adhere to precise language when students and teachers identify and distinguish the shapes of the flat surfaces as well as identifying the attributes (vertex/vertices, edges, faces).  It is difficult for children to visualize solid figures when they only look at a picture because the entire shape cannot be seen. Providing hands-on opportunities to examine three-dimensional figures and to construct them out of their two-dimensional faces will allow students to develop a deeper understanding and therefore make more precise visualizations.

Day 1 Essential Question: What two-dimensional shapes do you see on the flat surfaces of three-dimensional shapes?  Engage: Voyages Grade 2 Excursions: In Solid Form “Setting the Stage” p. 171-students get geometric solids to discuss the attributes.In Solid Form  Building Conceptual Knowledge: Students will identify attributes of solid figures and complete the chart in Voyages Grade 2 Excursions: Describe that Solid p. 245 in the student edition.  Follow the teacher’s edition sections “Setting the Stage” and “Building Conceptual Knowledge.” It is not necessary for students to complete the sections for the triangular or square pyramids, the triangular prism or the hexagonal prism. Information in the “Additional Information…” section does not need to be shared  Closure: Continue with “Building Skills and Strategies.” Students will explore visualization of hidden sides of solids and complete Which is the Base on p. 246 in the student edition.  Omit hexagonal prism By the end of Day 1, students should be able to identify the 2- dimensioanl shapes that make up a 3-dimensional shapes.

Day 2 Essential Question: How does knowing the number of vertices and edges help you build a solid figure?  Engage: Voyages Grade 1 Excursions: Caught in a Net, “Building Conceptual Knowledge” section. Students will create a human cube and a human rectangular prism with yarn and compare the attributes of both shapes.Caught in a Net  Make sure that the focus of the activity is to compare the attributes of a cube and rectangular prism. This task should take a minimal amount of time.  Building Conceptual Knowledge: Continue with the “Building Skills and Strategies” section where students construct three- dimensional shapes with gumdrops (or marshmallows) and toothpicks (or pretzel sticks).  Focus should be on the cube rather than the square based pyramid since the square based pyramid is not specified in the first grade standard.  Closure: Students complete p. 79 or record in their math notebooks. By the end of Day 2, students should be able to explain why knowing the number of vertices and edges will help them build a solid figure.

Day 3 Essential Question: How does knowing the flat surface of a three- dimensional shape help you build a solid figure?  Engage: Go Math Lesson 11.5, Listen and Draw p.473. Use the margin in the T.E. to guide your questions. Make sure to give the example of laying the cone on its side and trace it. Then ask students if it still makes a circle?  Building Conceptual Knowledge: Provide students with construction paper and a set of solid figures. With a partner students can trace the shapes and discuss how 2-dimensional shapes put together makes 3- dimensional shapes.  Use the On Your Own p. 475 #s 1-4 to informally assess your students.  Closure: Facilitate a discussion about how 2-dimensional shapes make up 3-dimensional shapes. By the end of Day 3, students should be able understand how knowing the flat surface of a 3-dimensional shape will help you build a sold figure.

Enrich/Reteach/Intervention  Reteach/Intervention:  Go Math Chapter 11 TE p. 473B Enrich Activity  Use an orange to model how a sphere does not make a circle when flattened. Bring an orange to class and a citrus peeler. Model for the students that when the skin is sectioned into 6 pieces and then peeled, the surface of the orange laid flat does not make a circle. This is proof that a sphere does not have any flat faces, only curved because the face has gaps when peeled back.  Go Math Reteach p. R90  Go Math Enrich p. E90 (this page is appropriate for remediation)  Enrich:  Go Math Chapter 11 E90 Shapes in Objects  3-D Rummy - Voyages Grade 2 Excursions, In Solid Form SE pp. 247 – 249 (TE p. 173) 3-D Rummy

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