Exploring 3D Objects

Overview

Lesson 2 of 15 in Shapes, Space and Reasoning. Learners handle real objects, match them to 3D models, and use precise mathematical language to describe faces, edges and vertices. The lesson is designed for five Year 4–6 learners and includes explicit visual demonstration, NZSL support and peer signing.

Learning intentions

• WALT identify common 3D objects.
• WALT describe 3D objects using faces, edges and vertices.
• WALT use mathematical vocabulary to explain our thinking.
• WALT compare objects and notice similarities and differences.

Success criteria

• I can name common 3D objects, such as a cube, cuboid, sphere, cylinder, cone and prism.
• I can identify faces, edges and vertices on a model or real object.
• I can describe an object using at least two properties.
• I can explain my thinking using words, drawings, symbols or NZSL.

Curriculum links

• Geometry: identifying, describing, classifying and comparing three-dimensional objects by their properties.
• Mathematical language and representations: communicating ideas using diagrams, labels, models and appropriate vocabulary.
• Mathematical reasoning: noticing patterns, making comparisons and justifying classifications.
• Thinking and relating to others: working collaboratively, listening, observing and responding to different representations.

Lesson structure (60 minutes)

1. 0–7 minutes – Visual hook and prior knowledge

Display a mystery photograph of a familiar object, such as a cereal box, ball or tin, using the visual introduction slides. Ask: “What 3D object does this remind you of? How do you know?” Learners silently show or sign an idea first, then share with a partner. Introduce the WALT and success criteria visually.

2. 7–17 minutes – Explicit teaching and modelling

Use a large model and the labelled faces, edges and vertices slides to demonstrate:

• A face is a flat surface.
• An edge is where two faces meet.
• A vertex is a corner where edges meet.

Trace each feature slowly, name it, show its NZSL sign where available, and invite learners to copy the sign. Model counting the features of a cube, including how to avoid counting the same feature twice. Clarify that some objects have curved surfaces and may have no vertices, such as a sphere.

3. 17–30 minutes – Tactile investigation

Place real objects and geometric models in the centre. Give each learner time to handle, turn and inspect them. In pairs, learners choose an object, name it, and identify at least two properties. They may record by drawing, writing numbers, using symbols or signing to a partner. Prompt with: “How many flat faces can you find?” “Where is an edge?” “Does it have any vertices?” Use the investigation instruction slide to keep the process visible.

4. 30–42 minutes – Match and explain

Mix the real objects with photographs and model images. Learners match each real object to its likely 3D model and explain one match to the group. Provide the 3D object investigation sheet for learners to record the object name, a sketch or photograph match, and properties. Encourage complete responses using the sentence frames:

• “This is a ______ because it has ______.”
• “I notice ______ faces and ______ vertices.”
• “It is similar to ______ but different because ______.”

Model and support NZSL vocabulary throughout. Peers take turns signing, pointing and explaining.

5. 42–53 minutes – Create a visual vocabulary chart

As a group, create a chart with columns for Object, Faces, Edges, Vertices, What it looks like and NZSL/visual cue. Each learner contributes one object. Add diagrams, symbols and clear labels. Discuss special cases: a sphere has no flat faces, edges or vertices; a cylinder has flat circular faces and curved edges; a cone has one vertex. Use the vocabulary chart and discussion slides for the shared examples.

6. 53–60 minutes – Share, assess and reflect

Display three objects or images. Each learner chooses one and gives a brief description using at least two properties, orally, through NZSL, pointing or a supported sentence frame. Ask: “Which objects have the same number of faces?” and “Which objects have the same number of vertices?” Learners self-assess against the success criteria with a visual signal. Record any vocabulary or counting errors to revisit next lesson.

Resources

• the 3D objects lesson deck
• the 3D object investigation sheet
• Real objects: box, dice, tin, ball, can, party hat and triangular prism
• Geometric models, if available
• Photographs or printed images of the real objects
• Large paper or whiteboard for the class vocabulary chart
• Thick pens, pencils and rulers
• Visual word cards for face, edge, vertex, flat, curved and corner
• NZSL signs or school-approved visual vocabulary references
• Optional phone or tablet camera for photographing matched objects

Assessment

• Observe whether each learner correctly identifies and counts faces, edges and vertices on selected models.
• Listen for accurate use of object names and property vocabulary during partner explanations.
• Review the 3D object investigation sheet and the final individual description against the success criteria. Accept spoken, signed, drawn and symbol-supported responses.

Differentiation

• Provide tactile objects, photographs, symbols, large labelled diagrams and sentence frames. Allow learners to respond through speech, NZSL, pointing, drawing or writing.
• Use partner modelling: one learner demonstrates tracing a face, edge or vertex while the other names or signs it, then swap roles.
• For learners needing support, begin with a cube, cuboid and sphere; mark a starting point with a removable sticker and count together.
• For advanced learners, compare objects with the same number of faces or vertices and explain how their faces, edges or surfaces differ. Investigate whether two different objects can share one property but not another.