340 Marshmallow and Toothpick Shapes Objective To provide experiences with building 2-dimensional and 3-dimensional shapes. Whole Group Small Group Partners Center Key Concepts and Skills • Construct 2- and 3-dimensional shapes and explore their properties. [Geometry Goal 1] • Identify names of 2- and 3-dimensional shapes. [Geometry Goal 1] Terms to Use dimension, 2-dimensional and 3-dimensional shape names Materials Home Link Master (Math Masters, p. 51); miniature marshmallows; round toothpicks; cardstock A Core Activities 䉴 Making Geometric Shapes Place marshmallows and toothpicks in the Math or Art Center. Demonstrate how to connect the toothpicks and marshmallows to make 2- and 3-dimensional shapes and structures, then encourage children to see what they can make with the materials. Children might make flat creations, or they might build upward or outward. They may make designs, discrete shapes (triangles, cubes, and so on), or representational models, such as houses or rocket ships. In each case, talk with children about the shapes you notice in their constructions (for example, a triangular roof on a 2-dimensional house or a cube as the base of a 3-dimensional house). Promote exploration and discovery with questions about children’s work, such as: How did you make that window? What shapes did you use? Have you figured out how to make a cube? How many marshmallows and toothpicks do you need? Can you think of a way to attach those triangles to each other? Place children’s shape creations on pieces of cardboard or cardstock and display them around the room. If you use portfolios, take photographs of children’s creations to place in their portfolios. Planning Tip Slightly stale marshmallows work best for this activity. Home Link 7 4 䉬 (Math Masters, p. 51) Name HOME LINK 7 4 Children use toothpicks and marshmallows to make shapes at home. 䉬 Family Note 䉴 Dividing Groups in Half (Revisit Activity 6䉬11, p. 304) Show children different numbers of marshmallows (some odd, some even). Have children work together to divide the collections in half. Discuss and try out children’s ideas for dividing the odd-numbered collections equally. Teaching Options EXTRA PRACTICE Using toothpicks and miniature marshmallows or gumdrops as building materials helps children develop their understanding of 2- and 3-dimensional shapes. Your child may use the materials to build structures (buildings, vehicles, 3-dimensional designs) that are made up of common geometric shapes. You can help your child learn more about shapes and numbers by talking about his or her project. You might ask questions such as: • • • • Are there any squares in your structure? How many triangles did you make? How many rectangles? Which shapes keep their shape the best? Do any shapes have more toothpicks than marshmallows or gumdrops? Build shapes and structures with toothpicks and marshmallows or gumdrops. Begin with flat 2-dimensional shapes, and then try building 3-dimensional shapes such as cubes, pyramids, and prisms. Copyright © Wright Group/McGraw-Hill B Date Building Geometric Shapes Bring one or two of your shapes to school. 䉴 Making Shapes with Straws Children who enjoy working with marshmallows and toothpicks might also enjoy the challenge of building shapes and structures with straws. Demonstrate how to connect straws by bending a twist tie or pipe cleaner in half and inserting half in the opening of one straw and half in the opening of another straw. (A small diameter straw works best.) Place the materials in a center and invite children to continue their shape explorations. Talk with children about the shapes they make. ART CONNECTION 䉴 Drawing with Shapes Read Picture Pie or Picture Pie 2 by Ed Emberley (Little Brown, 1984 and 1996) and show children how the author makes pictures using various shapes. Encourage interested children to experiment with these techniques on the writing and drawing pages in their math books. 341 Activity 7 4 Marshmallow and Toothpick Shapes 䉬 51 Math Masters, p. 51 Ongoing Assessment: Recognizing Student Achievement Use Dividing Groups in Half to assess children’s ability to model half of a collection. Children are making adequate progress if they understand that both halves must be equal. [Number and Numeration Goal 4]