Pull-Up Nets
Creating pull up nets is a great way for students to explore the relationship between two-dimensional shapes and three-dimensional solids.
Through this activity students can learn how a polyhedron is made up of multiple polygon faces, and are able to see how those different 2D shapes fit together in order to create the 3D objects. This activity can also be used to consolidate their knowledge of the names of different 2D shapes and 3D objects.
The Activity
Students cut out the template of the pull up net, punch holes through the small circles next to the numbers, and using a ruler, fold along the edge of each ‘face’.
Thread the string through the holes in number order, making sure the strung comes up through hole number 1, and down through the last hole.
Stick the face of the polyhedron with hole number 1 to the piece of paper.
Pull the string to make the net fold into your 3D solid.
Materials:
Nets Templates
Scissors
Glue
Ruler
String
Hole-Punch
Templates
Cube
Cube_template.pdfCuboid
cuboid_template.pdfTetrahedron
Tetrahedron_template.pdfOctahedron
Octahedron_template.pdfEnabling Prompts
Cut out the different nets and ask students what different shapes they can see within the 2D template.
Explore and play with premade pull-up nets.
Start with the simpler 3D objects, such as a cube, with step by step, specific instructions.
Extending Prompts
Attempt more complex pull up polyhedrons, e.g., octahedron.
Describe the features of each of the 3D objects: how many faces, corners, vertices? Are there any objects which have the same number of faces but still look different, why?
Decorate your nets! Can you make it so all your designs are facing upwards when the object is pulled up? Can you draw matching designs that end up being opposite each other when the object is pulled together?
Revelance to 21st Century Learning
Critical Thinking
Physically altering materials, as is done in activities involving folding paper, allows students to better visualise shapes from multiple different angles, and analyse their properties, which leads to a more comprehensive understanding of the geometric objects (Seah, 2015).
Communication
The anticipation of being able to transform one thing into another, in this case a flat piece of paper into a pop-up object, fosters a real curiosity and then wonderment. It gets students excited about how a shape comes to be, and why having certain properties can change a shape's form. This then encourages students to those ask questions and discuss their ideas with one another.
Creativity
The extension task of decorating the nets promotes creativity while linking the art with a critical thinking prompt.