Beginner sequence · Step 2 of 3
Start here
Readiness check: Students can identify the power source, input or switch, and output in a picture. Before class, rehearse the exact safe build with the listed components.
Exact starter recipe
POWER OFF. Arrange and label the parts first. Teacher-approved power (+) → input or switch → output with its required resistor/module → power (−). For this project: Build two separate LED branches connected to the same battery rails. Each LED must have its own resistor and matching polarity. Teacher checks the complete path before power-on. Disconnect power before every change.
Make the simplest version work first. Then use the test and extension in this lesson.
Teacher learning resources
Preview external resources before class. The circuit reference explains the science; use this page’s specified AA kit and connection list for the build.
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 job of the two-room paper house, its two success checks and the low-voltage safety limits.
What students show: Labeled input–output plan with criteria and constraints.3-5-ETS1-2
Compare two layouts or control ideas before choosing the easiest safe version to build and test.
What students show: Two small sketches and one criteria-based choice.3-5-ETS1-3
Use the same procedure for repeated trials: Run both lights for three 20-second trials, then gently cover one LED and confirm the other remains lit. Change one feature and repeat.
What students show: Before-and-after test record and evidence-based explanation.Materials
- two-AA covered battery holder
- two red LEDs
- two 330 Ω resistors
- copper tape
- cardstock house
- Planning pencil, circuit map, data table and printable student brief
- Color-coded component labels and teacher-prepared insulated leads
Teacher preparation
- Gather and verify these exact parts: two-AA covered battery holder; two red LEDs; two 330 Ω resistors; copper tape; cardstock house.
- Build and test one reference circuit using the manufacturer ratings; prepare a large color-coded connection diagram.
- Prepare the project structure and difficult cuts, stripped leads, motor hubs or sensor modules before students arrive.
- Set up a clearly marked POWER OFF build area, adult-check point and short powered-test area.
- Print the student brief and make a troubleshooting card: battery orientation → secure clips → resistor/module → LED polarity → switch gap.
Step by step
How to teach it
Name the job
- Make a paper house model with two room lights that can shine at the same time.
- Point out the input or switch and output. Read the two success checks and safety limits.
Model the circuit
- Teach parallel branches with a large diagram.
- Trace one complete path from positive to negative. Model power off before touching any connection.
Build with power off
- Build two separate LED branches connected to the same battery rails. Each LED must have its own resistor and matching polarity.
- Partners compare the real build with the diagram. No pair powers on before the adult check.
First safe trial
- Teacher checks voltage, resistor/module, polarity, secure parts and shorts.
- Run one brief trial, disconnect power and circle the first problem to fix.
Predict and reconnect
- Review the diagram and safety stop signs. Predict the test result.
- Reconnect only after the pair can explain the intended path.
Test and record
- Run both lights for three 20-second trials, then gently cover one LED and confirm the other remains lit.
- One partner operates while the other records; swap roles and keep conditions the same.
Troubleshoot one thing
- Disconnect power. Check one point at a time: source, connection, component direction, control, output.
- Change one feature, receive another adult check and repeat the test.
Explain and pack safely
- Demonstrate the working input-to-output action and use one recorded result in the explanation.
- Disconnect power. Adult collects batteries and modules; students return remaining parts.
Assessment
- Both room lights shine together
- Each branch includes its own resistor
- Student points to and names the power source, input/control and output.
- Build follows the teacher diagram and power-off safety routine.
- Student records repeated results and explains one revision.
Supports & extensions
- Provide a full-size color-coded diagram and place matching colored labels beside the real terminals.
- Offer preconnected resistor–LED modules, larger switches or prepared structures while preserving the input–output reasoning.
- Let students direct a partner, point to a diagram or dictate test evidence.
- Test the smallest working circuit before attaching it to the creative project.
- Extension after success: add one clearly labeled control or compare a second setting without changing the safe power source.
Safety & responsible use
- Use only the exact teacher-approved covered battery pack or classroom module listed; never use wall power, lithium cells, coin/button cells, or unknown power supplies.
- Power must be OFF before building or changing any connection. The teacher checks voltage, resistor values, polarity and possible shorts before power-on.
- Never connect battery terminals directly. Stop immediately and disconnect power if a component becomes warm, leaks, smells unusual or behaves unpredictably.
- Adults prepare wire ends, motor hubs and difficult holes. Cover sharp leads, secure moving parts, wear eye protection for guarded motor tests and keep liquids in a separate tray.
No-machine alternative
Use two paper light tokens on a drawn parallel-circuit map and trace two complete paths from positive to negative.
Printable student design brief
The challenge
Make a paper house model with two room lights that can shine at the same time.
Success criteria
- Both room lights shine together
- Each branch includes its own resistor
- Explain the power source → input/control → output path
Constraints
- Use only the listed teacher-approved low-voltage parts
- Power off before every connection change; adult approval before power-on
- No soldering, wall power, lithium cells or coin/button batteries
- Complete the working system and test record before decoration
Engineer’s notes
Printable beginner test record
Predict. Try. Improve.
Name ____________________ Partner ____________________
Our success rule: __________________________________________________
| Trial | Input / action | Expected result | First result | Result after one change |
|---|---|---|---|---|
| 1 | ||||
| 2 | ||||
| 3 | ||||
| 4 | ||||
| 5 | ||||
| 6 | ||||
| 7 | ||||
| 8 | ||||
| 9 | ||||
| 10 |
Use three rows for the introductory tests or all ten for switch reliability. Write the held, released, or other-key state for each sensing test.
One thing we changed: ______________________________________________
Things we kept the same: ____________________________________________
Our evidence shows: _________________________________________________
