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 bottle filter model that removes visible particles from muddy test water for observation only. 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: All water passes into the catch cup; Produces recorded clarity and time evidence.
What students show: A selected design with a reason connected to a success check.3-5-ETS1-3
Test, change one feature and retest: Teacher pours the same volume in three trials. Record time and compare visible clarity against a reference card. Change one layer order or thickness, rebuild with clean materials and repeat.
What students show: Before-and-after results collected under the same conditions.Materials
- Adult-cut clear bottle
- cotton
- gravel
- sand
- coffee filter
- muddy test water
- catch cup
- gloves
- tray
- Pencil, planning paper and the printable design brief below
Teacher preparation
- Gather per-pair materials: Adult-cut clear bottle; cotton; gravel; sand; coffee filter; muddy test water; catch cup; gloves; tray.
- Make one rough sample and rehearse the exact test: Teacher pours the same volume in three trials. Record time and compare visible clarity against a reference card.
- 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 bottle filter model that removes visible particles from muddy test water for observation only.
- Draw the bottle upside down and predict the order of large-to-fine filter layers.
- Students say what would count as a successful result.
Model the unfamiliar action
- Demonstrate slowly: Adult provides the cut bottle. Add a secured bottom filter, then measured material layers.
- Pause so partners can repeat the action; provide prepared parts if cutting or folding blocks progress.
Build the first version
- Place over the catch cup in a tray and label input and output as unsafe to drink.
- 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
- Teacher pours the same volume in three trials. Record time and compare visible clarity against a reference card.
- 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 layer order or thickness, rebuild with clean materials and repeat.
- Keep the original results rather than replacing them with only the best attempt.
Explain and clean up
- Submit the finished water filter model, 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
- All water passes into the catch cup
- Produces recorded clarity and time evidence
- Student demonstrates the actual task: Teacher pours the same volume in three trials. Record time and compare visible clarity against a reference card.
- 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 water filter model before decoration.
- Extension after success: choose one more value for the same tested feature, predict its effect and repeat teacher pours the same volume in three trials.
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.
- Test water is never for drinking. Wear gloves, keep hands away from faces, and let adults cut bottles and manage cleanup.
No-machine alternative
Use prepared paper parts, larger pieces or an adult-assisted version of the same build. Keep the functional task: Build a bottle filter model that removes visible particles from muddy test water for observation only. If physical testing is not possible, label sketches as predictions rather than measured results.
Printable student design brief
The challenge
Build a bottle filter model that removes visible particles from muddy test water for observation only.
Success criteria
- All water passes into the catch cup
- Produces recorded clarity and time evidence
- 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
