Net Detectives

Overview

Lesson 3 of 10 in Shape Shifters: Transformations. Students work in teams to match, create and explain nets for cubes, prisms and pyramids, using face shapes, symmetry and edge connections to justify whether a net will fold into a solid.

Learning intentions

• WALT identify the faces and properties of cubes, prisms and pyramids.
• WALT match a net to the three-dimensional shape it makes.
• WALT create and test nets by folding and visualising.
• WALT explain why a net is possible or impossible.

Success criteria

• I can name the two-dimensional faces in a net.
• I can check whether faces meet along suitable edges.
• I can use symmetry and face connections to predict whether a net will fold.
• I can explain my decision using mathematical vocabulary.

Curriculum links

• Geometry: identify and describe two- and three-dimensional shapes and their properties.
• Geometry: visualise, represent and construct three-dimensional objects from nets.
• Mathematical reasoning: communicate, justify and explain geometric ideas.
• Key competencies: thinking; managing self; participating and contributing; using language, symbols and texts.

Lesson structure (60 minutes)

1. 0–7 minutes – Hook and retrieval

Display an image of a flat cardboard net and the finished solid. Ask: “How can a flat shape become a box?” Students quietly sketch or describe what they notice. Open with the net-to-solid hook and retrieval slides and revisit vocabulary: face, edge, vertex, net, prism and pyramid.

2. 7–15 minutes – Explicit teaching

Show a cube, a rectangular prism and a square-based pyramid. Count and describe their faces, then demonstrate how a net must include every face and join faces along edges. Emphasise that matching the face shapes is not enough: faces must be connected in positions that allow the solid to close. Use the shape-properties teaching slides for diagrams and the prompts: “Which faces are next to each other?” and “What happens when this face folds?”

3. 15–20 minutes – Team challenge briefing

Place students in five teams of five, with roles such as reader, sorter, folder, recorder and spokesperson. Explain that teams must investigate nets, make a prediction before folding, and record evidence. Distribute the 3D shape nets pack and the net detective recording sheet. Model one example, including how to mark matching edges and write a justification.

4. 20–40 minutes – Net detective investigation

Teams sort the provided nets into cube, prism, pyramid or “not sure”, then test selected nets by cutting, folding and checking. They record the solid, face shapes, number of faces, prediction, result and explanation on the worksheet. Circulate and ask:

• “Which faces will become the base and sides?”
• “Do all the faces have a partner or connecting edge?”
• “Where is the line of symmetry?”
• “Which faces might overlap?”

Keep the investigation instruction and question slides visible. Support groups may use the physical templates directly; capable groups should first sketch or mentally fold before testing.

5. 40–53 minutes – Create and defend

Each team chooses one solid and creates a new net using paper, ruler and scissors. They label the faces and draw fold lines, then predict whether it will work before testing. Teams display one successful net and prepare a brief explanation using “Our net works because…” or “Our net does not work because…”. Use the create-and-defend prompt slides to structure presentations.

6. 53–60 minutes – Share and assess

Invite three or four teams to present different examples, including at least one unsuccessful net. Class members use thumbs up, sideways or down to indicate whether they agree, then ask for evidence rather than a guess. Finish with the plenary and exit-question slide: “What is the most important check when deciding whether a net will work?” Collect the worksheet for assessment.

Resources

• Teacher copies of a cube, rectangular prism and square-based pyramid
• Paper or thin card for student-designed nets
• Scissors, rulers, pencils and coloured pens
• Five sets of the 3D shape nets pack
• the net detective recording sheet, one per student or pair
• the Net Detectives slide deck
• Glue or tape, if students wish to reinforce a successful net
• Whiteboard for shared vocabulary and explanations

Assessment

• Observe team sorting and questioning, noting whether students identify face shapes, edge connections and symmetry rather than relying only on appearance.
• Check worksheets for accurate predictions, recorded folding results and explanations using evidence.
• Listen to presentations and use the final exit response to identify students needing further work with nets or three-dimensional shape properties.

Differentiation

• Support: provide physical solids and pre-cut templates; allow students to fold before explaining. Use guided prompts such as “How many faces are needed?” and “Which face is the base?”
• Support for EAL and SEN learners: display labelled diagrams and sentence frames, pair oral explanation with drawing, and assign a supportive team role. Reduce the number of nets to investigate without reducing the reasoning requirement.
• Extension: challenge students to identify an impossible net before folding, then explain precisely whether faces are missing, overlap, or are joined incorrectly.
• Further extension: ask students to find more than one valid net for the same solid and compare their symmetry and edge connections.