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 removable desk-edge guide that keeps three classroom cords separated and reachable. 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: Keeps three cords separated; Cords can be removed and returned by hand.
What students show: A selected design with a reason connected to a success check.3-5-ETS1-3
Test, change one feature and retest: Pull and return each cord five times. Record jams, cord crossings and guide movement. Change one channel width, clip position or lining and repeat.
What students show: Before-and-after results collected under the same conditions.Materials
- Cardboard
- felt scraps
- removable clips
- three unplugged practice cords
- ruler
- desk-edge model
- Pencil, planning paper and the printable design brief below
Teacher preparation
- Gather per-pair materials: Cardboard; felt scraps; removable clips; three unplugged practice cords; ruler; desk-edge model.
- Make one rough sample and rehearse the exact test: Pull and return each cord five times. Record jams, cord crossings and guide movement.
- 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 removable desk-edge guide that keeps three classroom cords separated and reachable.
- Measure cord thickness and the model edge. Draw three channels with finger access.
- Students say what would count as a successful result.
Model the unfamiliar action
- Demonstrate slowly: Layer cardboard into a stiff guide and line each broad channel with soft felt.
- Pause so partners can repeat the action; provide prepared parts if cutting or folding blocks progress.
Build the first version
- Attach to the model without glue and insert unplugged practice cords one at a time.
- 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
- Pull and return each cord five times. Record jams, cord crossings and guide movement.
- 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 channel width, clip position or lining and repeat.
- Keep the original results rather than replacing them with only the best attempt.
Explain and clean up
- Submit the finished desk cable guide, 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
- Keeps three cords separated
- Cords can be removed and returned by hand
- Student demonstrates the actual task: Pull and return each cord five times. Record jams, cord crossings and guide movement.
- 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 desk cable guide before decoration.
- Extension after success: choose one more value for the same tested feature, predict its effect and repeat pull and return each cord five times.
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.
- Use unplugged practice cords only. Never modify electrical cords or attach the guide to powered equipment.
No-machine alternative
Use prepared paper parts, larger pieces or an adult-assisted version of the same build. Keep the functional task: Build a removable desk-edge guide that keeps three classroom cords separated and reachable. If physical testing is not possible, label sketches as predictions rather than measured results.
Printable student design brief
The challenge
Build a removable desk-edge guide that keeps three classroom cords separated and reachable.
Success criteria
- Keeps three cords separated
- Cords can be removed and returned by hand
- 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
