Build a Net

Overview

Lesson 2 of 10 in Shape Shifters: Transformations. Students predict, test and explain which 2D nets fold to make familiar 3D shapes, connecting the faces in a net with the faces of the resulting solid. Students work in pairs, with access to paper nets and interactive net software.

Learning intentions

• WALT identify the 2D faces that make familiar 3D shapes.
• WALT investigate whether a net will fold into a closed solid.
• WALT explain how faces and edges in a net connect to form a 3D shape.
• WALT use mathematical language to describe prisms, pyramids, faces, edges and vertices.

Success criteria

• I can name the faces I see in a net.
• I can predict whether a net will fold into a particular 3D shape.
• I can test my prediction by folding paper or using interactive software.
• I can explain why a net does or does not make a closed solid.

Curriculum links

• Geometry: identify, describe and classify 2D shapes and 3D objects using their properties.
• Geometry: investigate transformations and visualise how shapes are changed or assembled.
• Mathematical communication: use diagrams, explanations and appropriate geometric vocabulary.
• Problem-solving and mathematical inquiry: make predictions, test ideas, justify conclusions and respond to others’ reasoning.

Lesson structure (60 minutes)

1. 0–7 minutes – Hook and prior knowledge Open with the introduction and hook slides. Show a flat net beside a closed box and ask: “How can a flat pattern become a solid shape?” Invite students to name familiar 3D shapes and recall faces, edges and vertices from the previous lesson.

2. 7–15 minutes – Model prediction and vocabulary Use the teaching slides about faces and nets to display a simple cube net. Model tracing each face, folding mentally along the edges and predicting which faces will meet. Emphasise that a net must fold into a closed solid without faces overlapping. Clarify prism, pyramid, face, edge and vertex.

3. 15–20 minutes – Explain the investigation Display the prediction–test–explain instructions. Put students into pairs and distribute the net investigation worksheet. Explain that for each net they must first record a prediction, then test it by folding paper or using interactive net software, and finally explain the result. Demonstrate how to record a net that fails because faces overlap or a gap remains.

4. 20–40 minutes – Pair investigation Give each pair paper, scissors and selected nets from the 3D shape nets pack. Students predict and test a range of nets for cubes, cuboids, prisms and pyramids. They may also rotate and unfold solids using the interactive net software. Circulate and ask: “How many faces should this solid have?”, “Which face will be the base?” and “Where will these edges meet?”

Support students with partially completed nets or a reduced selection of examples. Encourage confident students to test nets in different orientations and compare those that work with those that do not.

5. 40–52 minutes – Share and justify Return to the discussion and comparison slides. Select pairs to show one successful net and one unsuccessful net. Build a class explanation using the sentence frame: “We predicted ____. We tested it and found ____. It works/does not work because ____.” Record useful observations, such as a triangular prism having two triangular faces and three rectangular faces.

6. 52–60 minutes – Plenary and assessment Use the plenary question slide to display a new net. Students independently sketch or describe the solid it will make and explain one reason. Complete the final reflection on the conclusion and exit reflection section. Collect worksheets as students leave.

Resources

• the Shape Shifters lesson slide deck
• the net investigation worksheet
• the 3D shape nets pack
• Plain paper or card for additional nets
• Scissors and glue or tape
• Pencils, coloured pencils and rulers
• Several familiar 3D objects, such as a box, triangular prism or pyramid
• Interactive net software available on classroom devices
• Board or visualiser

Assessment

• Observe predictions and questioning during pair work, noting whether students identify faces and anticipate how they will meet.
• Check worksheets for accurate predictions, test results and explanations using face, edge, vertex, prism and pyramid appropriately.
• Use the plenary response to assess whether students can connect a 2D net with its resulting 3D solid and justify their thinking.

Differentiation

• Support: provide partially completed nets, fewer choices and a vocabulary bank with labelled diagrams. Allow students to fold with a partner and explain orally before writing.
• Support for EAL and learning needs: use real objects, gestures and colour-coded faces; provide sentence frames such as “This net makes a ___ because it has ___ faces.”
• Extension: design and draw more than one valid net for a prism or pyramid, then swap with another pair to test. Ask students to explain how their nets are different but produce the same solid.
• Encourage students needing motor support to use the interactive software or pre-cut nets, while maintaining the same prediction–test–explain thinking.