Cross Sections Discovery Lab | 7.G.A.3 | Hands-On + Digital | Grade 7 Geometry

⭐ CROSS SECTIONS DISCOVERY LAB — GRADE 7 MATH | 41-PAGE HANDS-ON + DIGITAL UNIT

Make CCSS 7.G.A.3 come alive with a multi-modal discovery lab that takes students beyond static worksheets and into real-world slicing, hands-on modeling, digital exploration, and rigorous mathematical practice.

This 41-page ready-to-teach resource helps Grade 7 students build spatial reasoning by predicting and analyzing the two-dimensional shapes created when three-dimensional figures are sliced. Students work with food models, Play-Doh, digital tools, and structured practice while connecting physical observations to mathematical vocabulary and cross-section concepts.

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📘 **TEACHER GUIDE — pp. 3–5**

• CCSS 7.G.A.3 alignment • 6 learning objectives with Bloom's verbs • Materials checklist • 3 implementation options: Full Lab, Digital Only, Paper Only • Differentiation notes for struggling, advanced, and ELL students

📗 **VOCABULARY FOLDABLE — pp. 6–11**

A 7-panel accordion foldable covering:

• Cross-section • Plane • Prism • Pyramid • Parallel slice • Perpendicular slice • Diagonal slice

Each panel includes a definition, labeled diagram, and real-world example.

🍎 **ACTIVITY 1 — REAL-FOOD SLICING PHOTO ANALYSIS — pp. 12–19**

Students analyze 12 illustrated food cards featuring examples such as bread, butter, cheese wheel, watermelon, cucumber, cake, celery, pineapple, orange, sandwich, ice cream cone, and Toblerone.

For each, students identify the three-dimensional figure and the resulting two-dimensional cross-section shape.

Includes a recording sheet and 5 discussion questions.

🟢 **ACTIVITY 2 — PLAY-DOH BUILD & SLICE LAB — pp. 20–23**

• Printable instructions with safety tips and materials list • Students build prisms and pyramids • Slice models horizontally, vertically, and diagonally using dental floss • 6-trial recording sheet with prediction and observation columns • Reflection questions

💻 **ACTIVITY 3 — DIGITAL DRAG-THE-PLANE — pp. 24–26**

• Links to 4 free digital tools: PhET, GeoGebra, IM, and NCTM • Predict-then-verify protocol • 14-row recording sheet covering 6 figures and 3 slice orientations • Pattern-discovery reflection questions

📝 **ACTIVITY 4 — PRACTICE PROBLEMS — pp. 27–36**

• 12 practice problems • Full-color labeled 3D diagrams • Progression from basic horizontal cuts to more advanced diagonal pyramid cuts producing trapezoids • Detailed answer key with step-by-step explanations for every problem

✏️ **QUIZ — pp. 37–40**

• 10 questions • 5 multiple choice • 4 short answer • 1 diagram-labeling question • Covers vocabulary, the four activities, and real-world application • Answer key with explanations and grading rubric

🙏 **REVIEW REQUEST PAGE — p. 41**

Branded thank-you and TPT review prompt.

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✦ **Multi-Modal Learning** — Combines physical Play-Doh modeling, visual food cards, digital exploration, and abstract mathematical practice.

✦ **Discovery Approach** — Students predict before slicing and then compare their predictions with observations.

✦ **Premium Design** — Full-color diagrams, branded layouts, and professional typography.

✦ **Flexible Implementation** — Options for 45-, 75-, or 120-minute use.

✦ **Safety Support** — Play-Doh activity includes allergy checks, floss-handling guidance, and cleanup procedures.

✦ **Classroom-Ready** — Print, copy, and teach with no additional preparation required.

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**CCSS.MATH.CONTENT.7.G.A.3**

Describe the two-dimensional figures that result from slicing three-dimensional figures, as in plane sections of right rectangular prisms and right rectangular pyramids.

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**Full Lab:** 90–120 minutes, suitable for 2 periods or 1 block

**Grouping:** Pairs for Activities 2–3; individual work for Activities 1 and 4

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• Grade 7 Math

• CCSS 7.G.A.3 instruction

• Geometry units involving cross sections

• Hands-on math labs

• Digital math exploration

• Interactive classroom activities

• Small-group instruction

• Visual and experiential learning

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Download the preview to see 10 sample pages and a contents overview showing the components of the complete 41-page unit.

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