For teachers
Engineering standards
This shows how the lesson connects to the national NGSS engineering standards and what student work you can collect.
3-5-ETS1-1
Define the need in Build a two-level cardboard shelf using removable folded connectors instead of permanent glue. Agree on the two success checks and the listed material limits.
What students show: Two labeled ideas with the target and limits stated.3-5-ETS1-2
Compare the ideas using the project checks: Supports six counters across two levels; Can be assembled and disassembled three times.
What students show: A selected design with a reason connected to a success check.3-5-ETS1-3
Test, change one feature and retest: Load three counters per shelf, move the unit 1 m and disassemble it in three rounds. Change one slot width, fold or connector length and repeat.
What students show: Before-and-after results collected under the same conditions.Materials
- Cardboard panels
- cardstock connector strips
- ruler
- six large counters
- tape only for connector prototypes
- Pencil, planning paper and the printable design brief below
Teacher preparation
- Gather per-pair materials: Cardboard panels; cardstock connector strips; ruler; six large counters; tape only for connector prototypes.
- Make one rough sample and rehearse the exact test: Load three counters per shelf, move the unit 1 m and disassemble it in three rounds.
- Set the size, load or distance marks mentioned in the steps before class. Demonstrate an ordinary first attempt, not a perfect model to copy.
- Prepare any holes, fasteners or difficult cuts for students. Check the stated safety note and clear the testing space.
Step by step
How to teach it
See the job and plan
- Introduce the finished object: Build a two-level cardboard shelf using removable folded connectors instead of permanent glue.
- Measure panel thickness and draw corner and T-shaped connectors with labeled slots.
- Students say what would count as a successful result.
Model the unfamiliar action
- Demonstrate slowly: Fold and test one connector around scrap cardboard before making a matching set.
- Pause so partners can repeat the action; provide prepared parts if cutting or folding blocks progress.
Build the first version
- Assemble base, sides and middle shelf. Adjust connectors until panels meet squarely.
- Partners swap builder and checker roles halfway through. Check the working part before decorating.
Try once and save
- Run one trial of the stated test to locate an obvious problem. Do not count a changed procedure as a fair comparison.
- Label and store the model; sketch its current shape and clear the work area.
Predict and set up
- Revisit the two success checks. Agree on identical starting conditions and prepare a before/after results table.
Collect evidence
- Load three counters per shelf, move the unit 1 m and disassemble it in three rounds.
- One student operates while the other records. Swap for a later trial while noting a change of operator if it affects the result.
Change one thing
- Change one slot width, fold or connector length and repeat.
- Keep the original results rather than replacing them with only the best attempt.
Explain and clean up
- Submit the finished mini modular shelf, two labeled ideas and before-and-after evidence. Explain which change the results support.
- Collect the brief and results; separate reusable materials and clean the test area.
Assessment
- Supports six counters across two levels
- Can be assembled and disassembled three times
- Student demonstrates the actual task: Load three counters per shelf, move the unit 1 m and disassemble it in three rounds.
- Record includes failures as well as successes.
- Student identifies one changed feature and uses the retest to explain the result.
Supports & extensions
- Provide a worked first joint or sample; have students record dimensions and explain one comparison limitation.
- Start with the smallest working version of mini modular shelf before decoration.
- Extension after success: choose one more value for the same tested feature, predict its effect and repeat load three counters per shelf, move the unit 1 m and disassemble it in three rounds.
Safety & responsible use
- Teacher checks materials and test conditions before use. Use classroom scissors; adults prepare difficult cuts, holes and fasteners.
- No powered tools, coding, hot glue or electrical circuits are required. Keep moving objects contained and test loads light.
- Keep pieces on the tabletop, do not mouth materials and stop if a part tears into a sharp or loose hazard.
No-machine alternative
Use prepared paper parts, larger pieces or an adult-assisted version of the same build. Keep the functional task: Build a two-level cardboard shelf using removable folded connectors instead of permanent glue. If physical testing is not possible, label sketches as predictions rather than measured results.
Printable student design brief
The challenge
Build a two-level cardboard shelf using removable folded connectors instead of permanent glue.
Success criteria
- Supports six counters across two levels
- Can be assembled and disassembled three times
- Record the stated test and explain one revision
Constraints
- Use only the listed teacher-approved materials
- Stay within the teacher-set size, load and test-space limits
- Two 45-minute meetings; keep the first version simple
