Making new shapes with shapes

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SWBAT construct composite plane shapes and use them to construct new 3D shapes.

Big Idea

My first graders have been studying the defining attributes of 2D shapes. They are going to love using toothpicks and marshmallows to present their knowledge of 2D and create 3D shapes.

Rev Them Up

5 minutes

I will be introducing my students to 3-dimensional shapes in this lesson: cube, rectangular prism, sphere, cone, pyramid, and cylinder.

My discussion will cover:

  • 3D shapes are made up of plane shapes.
  • 3D shapes have length, width, and height.
  • 3D shapes have faces, edges, and vertices.

You can see the beginning of our discussion on the video in the resource section. Here is a great slideshow to help introduce the 3D shape vocabulary terms.

Whole Group Interaction

15 minutes

I will continue my discussion of shapes and help my students identify what 2D shapes compose each 3D shape.

  • cylinder: circles
  • rectangular prism: squares and rectangles
  • sphere: none
  • cone: circle
  • cube: squares
  • pyramid: square and triangles

I will be discussing each 3D shape example I have with my students for them to help me determine which ones they would be able to make in our independent practice using toothpicks and marshmallows. In our discussion I want my students to develop an understanding of plane and solid figures. I want them to master their CCSS to construct composite shapes and then use those shapes to build other composite shapes (1.G.A.2). As they build these shapes they will recognize them from different perspectives. This will help them in later grades when they are studying angles and learning additional shapes and their attributes.

Independent Practice

15 minutes

I want my students to build composite shapes from toothpicks and marshmallows. Then I want them to use those shapes to piece together additional 3D composite shapes. They are looking for structure and using this structure to further their ideas. (MP7). This is a great skill to have for math because there are patterns and connections across the board. If they can see that a cube is made from 8 squares then they have used the given structure of seeing a square and figured out how to add more to develop a cube. Here students are building several composite shapes.

I will show them how to stab their toothpicks into the marshmallows and slowly add to it to form their shapes.  I will begin by showing them an example of building a cube. I will build two squares and then hold up my cube example and ask what do I need to add to get my edges and faces. I will pass out most of the supplies and put the extra at a central location. I will tell them to begin building their choice of a 3D shape, but if they need more materials go get them and if the finish with extra, please put them back. I will allow them to build 2 shapes each.


5 minutes

To finalize our lesson and offer my students an opportunity to develop some mental imagery, I am going to ask a few questions and cold call on those that raise their hand.

  • What plane shapes make up a cube? (square)
  • What plane shapes make up a rectangular prism? (rectangle and square)
  • What plane shapes make up a pyramid? (triangle and square)