Polyhedra: Faces, edges, and verticies (3-D marshmallow models)
Students will review the names of 3 dimensional shapes, create the shapes using marshmallows and toothpicks, and find relationships among the faces, verticies, and edges of different 3-D polyhedra.
A lesson plan for grade 3 Mathematics
Students will create polyhedra using marshmallows or gumdrops and be able to identify and find relationships in the number of verticies, edges, and faces.
Time required for lesson
- Solid figures
- Marshmallows or Gum Drops (about 30 per student)
- Toothpicks (about 30 per student)
- Chart- including verticies, edges, and faces
- File folder
Students will need to be familiar with polyhedra and their names.
- Introduce the topic by showing several of the wooden or plastic geometric polyhedra. Have students name the polyhedra and where they could be found in their environment.
- Tell the students that now you are going to play a game with the shapes. Place a file folder on the overhead (Opened and right side up so that it creates a visual barrier between the over head and the students.) Place one shape on the overhead. Have students guess what 3-D shape the face belongs to. Place several of the shapes on the overhead one by one. Play the game until the students feel like they have caught on to the game.
- Explain to the students that what they just looked at were the faces of these 3-D shapes. Hand out 3-D shapes to students. Give each student one polyhedra each. Hand out large index cards. Have students to turn to the unlined side and draw a face of their object. Then, have them to trace another face. Allow the students to create a riddle on the unlined side of their card at the bottom. Model a riddle: I have 6 faces. All of my faces are squares. What am I? have students put the answer to their riddle on the lined side of the card.
- Once students have created their riddle, have them read some to the class. Allow the class to guess what the polyhedra is.
- Explain to students where the faces, edges, and verticies of three dimensional objects are located.
- Hand out marshmallows or gumdrops and toothpicks to each student or to partners. Hand out recording chart to record number of faces, verticies, and edges of each shape they will create. Tell students that the toothpicks will represent the edges and the marshmallows will represent the verticies.
- Direct and model students through the first 3-D shape. Create a triangular pyramid using toothpicks and marshmallows. Record the number of faces, edges, and verticies.
- Ask students to create a cube and square pyramid. You may allow them to create other geometric shapes with the remainder of their supplies. Students should record faces, verticies, and edges for the cube and square pyramid.
- Once all groups have created each model, bring the class back together and discuss the relationships on the chart that they have created. You will want to see if students see patterns in number of faces to edges, edges to verticies, and faces to verticies. Students will recognize some of these relationships.Use a hypothetical 3-D shape with a certain amount of faces. Have the students to tell you how many verticies or edges that the shape would have.
- Have the students review the parts of 3-D shapes. They may use their models to explain each part. Have students to write 2 things that they learned from this class on a piece of paper. They may hand this paper to you as they exit for their “Ticket-Out-the-Door.” You may keep the models and they will harden overnight. (You can paint them with tempra paint OR you can let the students eat the models!)
Review the written comments on paper. If the student has given 2 reasonable responses to the day’s material, then they will receive a 100. If the student has only listed 1 reasonable comment, they will receive a 50. However, if the student has no comments listed, they will receive a 0.
This lesson can be broken into a period of two or three days. You may also want to give the students extra toothpicks and gumdrops to create their own 3 dimensional shapes.
North Carolina curriculum alignment
- Goal 3: Geometry - The learner will recognize and use basic geometric properties of two- and three-dimensional figures.
- Objective 3.01: Use appropriate vocabulary to compare, describe, and classify two- and three-dimensional figures.