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 four-step tabletop chain reaction in which one action starts the next and the final step tips a paper cup. 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: Includes four visible connected actions; Tips the final paper cup in at least three of five trials.
What students show: A selected design with a reason connected to a success check.3-5-ETS1-3
Test, change one feature and retest: Run from the same start five times. Record the last completed step and where the chain stopped. Change one spacing, angle or target position. Reset carefully and repeat five trials.
What students show: Before-and-after results collected under the same conditions.Materials
- Cardboard ramp
- large wooden ball
- domino blocks
- craft sticks
- paper cup
- tape
- ruler
- Pencil, planning paper and the printable design brief below
Teacher preparation
- Gather per-pair materials: Cardboard ramp; large wooden ball; domino blocks; craft sticks; paper cup; tape; ruler.
- Make one rough sample and rehearse the exact test: Run from the same start five times. Record the last completed step and where the chain stopped.
- 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 four-step tabletop chain reaction in which one action starts the next and the final step tips a paper cup.
- Draw four boxes showing the action order: release, roll, knock, and tip. Add arrows between every step.
- Students say what would count as a successful result.
Model the unfamiliar action
- Demonstrate slowly: Build a low ramp and place the large ball at a marked start. Arrange large blocks with safe, reachable spacing.
- Pause so partners can repeat the action; provide prepared parts if cutting or folding blocks progress.
Build the first version
- Add one craft-stick lever or bridge if needed, then place the paper-cup target at the final position.
- 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
- Run from the same start five times. Record the last completed step and where the chain stopped.
- 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 spacing, angle or target position. Reset carefully and repeat five trials.
- Keep the original results rather than replacing them with only the best attempt.
Explain and clean up
- Submit the machine, sequence drawing and ten-run record. Explain how one small change affected later steps.
- Collect the brief and results; separate reusable materials and clean the test area.
Assessment
- Includes four visible connected actions
- Tips the final paper cup in at least three of five trials
- Student demonstrates the actual task: Run from the same start five times. Record the last completed step and where the chain stopped.
- 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 chain-reaction machine before decoration.
- Extension after success: choose one more value for the same tested feature, predict its effect and repeat run from the same start 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 the machine on one table with large pieces only. No projectiles, falling weights, fire, liquids, or traps are allowed.
No-machine alternative
Use prepared paper parts, larger pieces or an adult-assisted version of the same build. Keep the functional task: Build a four-step tabletop chain reaction in which one action starts the next and the final step tips a paper cup. If physical testing is not possible, label sketches as predictions rather than measured results.
Printable student design brief
The challenge
Build a four-step tabletop chain reaction in which one action starts the next and the final step tips a paper cup.
Success criteria
- Includes four visible connected actions
- Tips the final paper cup in at least three of five trials
- 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
