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 Make simple folded-card tongs that pick up a large paper ball without touching it with your fingers. 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: Picks up and releases the paper ball; Reopens without tearing.
What students show: A selected design with a reason connected to a success check.3-5-ETS1-3
Test, change one feature and retest: Move the same large paper ball between cups five times. Record drops and whether the arms reopen. Change one grip pad or arm fold. Repeat the same pickup task.
What students show: Before-and-after results collected under the same conditions.Materials
- Folded card strip
- tape
- paper grip pads
- large paper ball
- two cups
- Pencil, planning paper and the printable design brief below
Teacher preparation
- Gather per-pair materials: Folded card strip; tape; paper grip pads; large paper ball; two cups.
- Make one rough sample and rehearse the exact test: Move the same large paper ball between cups five times. Record drops and whether the arms reopen.
- 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: Make simple folded-card tongs that pick up a large paper ball without touching it with your fingers.
- Draw the tongs open and closed. Mark where your hand presses and where the ball is gripped.
- Students say what would count as a successful result.
Model the unfamiliar action
- Demonstrate slowly: Fold a broad card strip in half to make two arms. Keep the folded end flexible.
- Pause so partners can repeat the action; provide prepared parts if cutting or folding blocks progress.
Build the first version
- Add small folded-paper grip pads to the inside tips and keep them lined up.
- 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
- Move the same large paper ball between cups five times. Record drops and whether the arms reopen.
- 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 grip pad or arm fold. Repeat the same pickup task.
- Keep the original results rather than replacing them with only the best attempt.
Explain and clean up
- Demonstrate the tongs with a movement sketch and five-transfer record.
- Collect the brief and results; separate reusable materials and clean the test area.
Assessment
- Picks up and releases the paper ball
- Reopens without tearing
- Student demonstrates the actual task: Move the same large paper ball between cups five times. Record drops and whether the arms reopen.
- Record includes failures as well as successes.
- Student identifies one changed feature and uses the retest to explain the result.
Supports & extensions
- Provide fold marks or pre-cut parts; accept drawings or dictated observations.
- Start with the smallest working version of paper ball tongs before decoration.
- Extension after success: choose one more value for the same tested feature, predict its effect and repeat move the same large paper ball between cups 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.
- 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: Make simple folded-card tongs that pick up a large paper ball without touching it with your fingers. If physical testing is not possible, label sketches as predictions rather than measured results.
Printable student design brief
The challenge
Make simple folded-card tongs that pick up a large paper ball without touching it with your fingers.
Success criteria
- Picks up and releases the paper ball
- Reopens without tearing
- 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
