Build, Calculate, Present

This is lesson 8 of 8 in the unit "Similarity to Solid Design". Lesson Title: Build, Calculate, Present Lesson Description: Length: 30 minutes. Objective: complete the model, verify calculations, and communicate design decisions. Warm-up (2): checklist—dimensions, units, tabs, labels, calculator settings. Mini-lesson (4): model an SA table: Component A type/dimensions, face areas, SA; Component B type/dimensions, face areas, SA; hidden joins; total exposed SA. Guided practice (4): teams peer-check one another’s nets using “Does it fold? Does every shared edge match? Are all dimensions labelled?” Independent/collaborative studio (13): finish construction, calculate each component’s SA and total composite SA, mark hidden faces, and rehearse presentation. Assessment checkpoint: teacher records completion of net, similarity evidence, component calculations, composite calculation, and labels/units. Closure/presentation (7): 1-minute gallery presentations or paired presentations: theme, similarity evidence, component SA, hidden joins, total SA, one design choice. Final submission must include model, planning template, nets, calculations, labelled dimensions/units, presentation notes, and reflection. Reflection prompts: What was strongest mathematically? Which measurement or net caused difficulty? How did you revise? What would you improve? Analytic rubric, 4 points each, total 24: Mathematical accuracy—4 consistently correct dimensions, units, formulas, and arithmetic; 3 mostly correct with minor errors; 2 several errors but reasoning visible; 1 limited evidence. Similarity reasoning—4 clearly identifies corresponding parts, proportional ratios, scale factor, and justification; 3 mostly complete; 2 partial or unclear; 1 absent/incorrect. Net/design construction—4 accurate, complete, neatly folded, stable, creative composite with tabs; 3 functional with minor inaccuracies; 2 partly functional or incomplete; 1 minimal construction. Surface-area calculations—4 accurate SA for every component, hidden joins, and total exposed SA; 3 mostly accurate; 2 some components or joins missing; 1 little evidence. Communication—4 clear labelled diagrams, organized work, units, and confident explanation; 3 understandable with minor omissions; 2 difficult to follow; 1 minimal communication. Reflection—4 specific, thoughtful evidence-based reflection and revisions; 3 clear reflection; 2 general reflection; 1 incomplete. Materials: completed models, rubric, peer-check sheet, calculator, presentation cards. Differentiation: allow recorded or teacher-supported presentation, enlarged labels, oral calculation explanation, and extra construction time. Management: one cutter per table at a time, glue caps closed, cleanup timer, models carried with two hands, final tool count.

Overview

In this final studio lesson, students complete and verify a composite solid model, calculate the surface area of each component and the total exposed surface area, and communicate how similarity guided their design. The lesson consolidates prior work with scale factors, nets, measurement, surface-area formulas, and mathematical communication.

Learning intentions

Students will:

complete and test a stable composite solid model.
use corresponding dimensions and scale factors to explain similarity.
calculate component and total exposed surface area, including hidden joins.
communicate design decisions using labelled diagrams, units, calculations, and reflection.

Success criteria

I can show which parts of my design are similar and justify the scale factor.
I can calculate the surface area of every component and subtract hidden joined faces.
I can label dimensions and units clearly and explain one design decision.
I can identify a difficulty, describe a revision, and suggest an improvement.

Curriculum links

Shape and Space — apply formulas and measurement to calculate surface area of composite three-dimensional objects.
Shape and Space — construct and interpret nets and use geometric properties to solve practical design problems.
Number and algebraic reasoning — use proportional relationships, scale factors, and accurate operations with rational numbers.
Mathematical processes — problem solving, reasoning, communication, connections, and technology use through calculator-supported design work.

Lesson structure (30 minutes)

0–2 min · Warm-up checklist. Display the opening checklist slide and ask students to confirm dimensions, units, tabs, labels, and calculator settings before handling materials. Students silently check their model and planning template, then identify one item needing attention.
2–6 min · Mini-lesson: surface-area table. Use the model surface-area table to demonstrate a clear record:

Component A: type and dimensions, each face area, then total surface area.
Component B: type and dimensions, each face area, then total surface area.
Hidden joins: identify shared faces and subtract them from the component total.
Total exposed surface area: add component areas and subtract all hidden faces.

Emphasize square units, correct formulas, and checking calculator entries. Students compare the example with their own planned components and ask questions about any hidden face.

6–10 min · Guided peer check. Display the net-check questions and pair teams to inspect one another’s nets. Students use the questions, “Does it fold? Does every shared edge match? Are all dimensions labelled?” They give one accurate observation and one specific revision suggestion before returning the work.
10–23 min · Collaborative design studio. Reopen the studio workflow slide and have teams finish construction, calculate each component’s surface area, mark hidden faces, and calculate total exposed surface area. Students label all dimensions and units, record similarity evidence and scale factor, and rehearse a concise presentation using the final design calculation and presentation sheet. Only one cutter is used per table at a time; glue caps remain closed when not in use. During the studio, record whether each team has completed its net, shown similarity evidence, calculated component and composite surface area, and included labels and units.
23–30 min · Gallery presentations and closure. Use the presentation prompts and reflection slide. Each team gives a one-minute gallery or paired presentation covering its theme, similarity evidence, component surface area, hidden joins, total surface area, and one design choice. Students submit the model, planning template, nets, calculations, labelled dimensions and units, presentation notes, and reflection. If time allows, partners share one strength and one next step before the cleanup timer begins.

Resources

Completed models and construction materials
Build, Calculate, Present slide deck
final design calculation and presentation sheet
Analytic rubric
Peer-check sheet
Calculators
Presentation cards
Rulers, pencils, scissors, glue, and labels
Cleanup timer and final tool-count list

Assessment

During peer checking and studio work, use observation and questioning to assess folding accuracy, matching edges, similarity evidence, formulas, arithmetic, hidden joins, labels, and units.
Record the checkpoint evidence: completed net, similarity reasoning, component calculations, composite calculation, and clear labels/units.
Assess the final submission with the six-category analytic rubric, four points per category (24 points total): mathematical accuracy, similarity reasoning, net/design construction, surface-area calculations, communication, and reflection. For each category, award 4 for consistently accurate, complete, and well-justified work; 3 for mostly correct work with minor omissions; 2 for partial work with visible reasoning; and 1 for limited, absent, or incorrect evidence.

Differentiation

Provide an enlarged checklist and labels, pre-marked or partially completed calculation tables, formula reminders, and teacher-supported checking of hidden joins.
Allow students to explain calculations orally, use a recorded presentation, or present with teacher support rather than speaking independently.
Offer extra construction time and assign practical roles such as builder, calculator checker, label checker, and presenter.
Extend confident students by asking them to verify surface area using a second method or explain how changing the scale factor would affect the design. Use clear visuals, worked examples, repeated instructions, and strategic pairing for EAL and students requiring additional support.

Cleanup: start the timer, close glue caps, count all tools, and have students carry models with two hands.