Project Nets Together

Overview

In this sixth lesson of the eight-lesson unit, students turn their approved designs into accurate three-dimensional models. They apply scale factor, measurement, properties of similar shapes, and surface-area reasoning while constructing, testing, and improving nets.

Learning intentions

Students will:

• create an accurate, labelled net for a three-dimensional model;
• use dimensions, fold lines, tabs, and colour-coding to communicate their design;
• construct a model safely and test its fit and stability;
• explain how similar shapes and scale factor appear in their model.

Success criteria

• I can draw or use a net with accurate dimensions and clearly labelled faces.
• I can distinguish cut lines, fold lines, and glue tabs.
• I can use colour to identify corresponding similar shapes.
• I can assemble a model that fits, stands, or closes as intended and describe one improvement.

Curriculum links

• Number — demonstrate an understanding of scale factor and apply it to similar shapes.
• Shape and Space — determine surface area using nets and appropriate measurement strategies.
• Shape and Space — analyse and construct three-dimensional objects from two-dimensional representations.
• Mathematical Processes — communicate mathematical thinking, make connections, and use problem-solving strategies.

Lesson structure (30 minutes)

1. 0–4 min · Reconnect and hook. Teacher displays the opening and comparison images in the project introduction deck and asks, “What would make a net accurate enough to become a stable model?” Students identify likely failure points from their approved designs, such as mismatched edges, missing tabs, or incorrect scale.

2. 4–9 min · Demonstrate construction. Teacher uses the construction demonstration slides to model transferring dimensions, labelling faces, colour-coding corresponding similar shapes, marking fold lines differently from cut lines, and adding tabs only where they are needed. Demonstrate safe cutting on a mat, folding without tearing, and checking that joining edges have equal lengths. Students annotate their design checklist and ask clarifying questions.

3. 9–19 min · Create and assemble. Teacher distributes the net construction and checkpoint sheet and provides paper, rulers, pencils, coloured pencils, scissors, and glue. Students draw or trace their approved net, add all labels and fold lines, colour-code corresponding shapes, then cut and assemble their model. Before cutting, each student completes the worksheet accuracy check; the teacher circulates and approves nets, checking dimensions, tabs, and corresponding edges.

4. 19–24 min · Fit and stability test. Teacher uses the testing and troubleshooting slides to introduce three tests: Does it close or join correctly? Do corresponding edges match? Does it remain stable when placed on a desk? Students test their models, record results on the worksheet, and make one controlled adjustment if necessary. Partners may hold pieces, compare edge lengths, or read the checklist aloud, but each student explains their own mathematical decisions.

5. 24–28 min · Checkpoint 2/3. Teacher conferences briefly with pairs or individuals using the checkpoint prompts in the net construction and checkpoint sheet: “Where is scale factor visible?” “Which faces are similar?” “How did the net help you reason about surface area?” Students show the net and assembled model, identify one successful feature, and name one revision or next step. Record “complete,” “revise,” or “teacher support required.”

6. 28–30 min · Plenary and reset. Teacher displays the reflection prompts in the testing and reflection slides and invites two students to share different solutions to a construction problem. Students complete the final worksheet reflection, return scraps and tools, and store models safely for the next lesson.

Resources

• the project introduction deck
• the net construction and checkpoint sheet
• Approved student design sketches from Lesson 5
• Plain paper or cardstock
• Rulers, pencils, coloured pencils or markers
• Scissors and cutting mats
• Glue sticks or tape
• Sample net and completed model
• Student folders or trays for storing models

Assessment

• During demonstration and construction, check whether students accurately distinguish cut lines, fold lines, tabs, dimensions, and corresponding faces.
• Use the worksheet accuracy check and teacher conference to assess application of scale factor, similarity, and surface-area reasoning.
• Collect the model and final reflection as evidence for Checkpoint 2/3. Look for an accurate net, successful assembly or justified revision, and a clear explanation of one mathematical choice.

Differentiation

• Provide pre-cut nets, partially completed nets, larger paper, or teacher-supported cutting for students who need fine-motor, processing, or time support. Reinforce safe scissor use and allow a partner to hold the ruler or model.
• Offer a visual key on the board: solid line = cut, dashed line = fold, shaded flap = tab. Use a worked sample and have students check one edge pair at a time.
• Support EAL learners with illustrated terms such as face, edge, vertex, net, fold, tab, similar, and scale factor; provide sentence starters: “These faces are similar because…” and “I changed ___ so that…”
• Extend ready students by asking them to calculate the model’s surface area from the net, compare it with the original design, or justify whether doubling every length doubles, quadruples, or otherwise changes the surface area.