First 9V Circuit

Overview

In this fifth lesson of “Circuits, Current, and Creativity,” students move from discussing circuit components to assembling and testing a simple circuit. With explicit safety guidance, teams identify battery polarity, create a closed loop, observe an LED or motor, and record evidence in a structured results table.

Learning intentions

Students will be able to:

• Identify the positive and negative terminals of a 9V battery and the polarity of an LED or motor.
• Assemble a complete circuit using a battery, wires, and an LED or motor.
• Explain that a circuit must form a closed loop for current to flow.
• Record observations accurately and discuss results using evidence.

Success criteria

• I can identify the positive and negative sides of the components I use.
• I can build a closed circuit without unsafe connections.
• I can describe what happened when the circuit was open or closed.
• I can record clear observations in a table and use them to explain my results.

Curriculum links

• Science and Engineering Practices: planning and carrying out an investigation, recording observations, and using evidence to communicate an explanation.
• Washington State Common Core literacy in science and technical subjects: follow a multistep procedure and describe the sequence of steps accurately.
• Washington State Common Core speaking and listening: participate in collaborative discussions, build on others’ ideas, and explain observations clearly.
• Mathematics — rational number addition and additive inverses: students connect “opposite” terminals and directional polarity to the idea that opposite quantities can combine to make zero, preparing for later quantitative circuit work.

Lesson structure (40 minutes)

1. 0–5 min · Hook and prediction. Open with the circuit mystery hook and display a battery, wires, and LED or motor without connecting them; students sketch or verbally predict what must happen for the device to work. Emphasize that electricity requires a safe, complete path and ask: “What could stop the circuit from working?”

2. 5–12 min · Safety and direct instruction. Use the safety and circuit-model slides to model the components, positive and negative terminals, LED polarity, and a closed loop. Demonstrate one safe connection, keeping the 9V battery disconnected until the circuit is ready; explain that students must never connect the battery terminals directly with a wire, touch bare conductors unnecessarily, or force components together. Students repeat the safety rules and identify the positive and negative connection points on their equipment.

3. 12–16 min · Procedure and roles. Display the team procedure slide and distribute the 9V circuit investigation sheet to each student or pair. Assign teams of three roles—Builder, Safety Checker, and Recorder—and have students read the procedure, label their components, and predict whether the LED or motor will operate when the loop is closed.

4. 16–29 min · Build and test. Teams assemble the 9V battery, wires, and LED or motor, checking polarity and the closed loop before connecting the battery. The Safety Checker asks, “Is the path complete? Are the battery terminals protected? Is the component connected correctly?” before the Builder makes the final connection; students test one change at a time, observe the result, and record whether the device operates, does not operate, or behaves unexpectedly. Circulate to inspect connections and ask, “Where does the path begin, and where does it end?”

5. 29–36 min · Troubleshoot and discuss evidence. Pause teams for a brief comparison using the troubleshooting and discussion slides; invite groups with different results to describe their setup without touching another team’s circuit. Students compare observations, check polarity, look for loose wires or an open loop, and revise one connection if needed. Each team completes the explanation sentence on the worksheet: “Our device [worked/did not work] because…”

6. 36–40 min · Plenary and exit check. Use the final reflection slide and have students complete the final response on the 9V circuit investigation sheet before materials are returned. Students draw a simple closed-loop circuit, mark positive and negative terminals, and answer: “What is one safety rule and one piece of evidence from today’s test?”

Resources

• DIY STEM kits with 9V batteries, battery connectors, insulated wires, LEDs, and/or small motors
• One teacher demonstration circuit
• the circuit mystery and instruction deck
• the 9V circuit investigation sheet
• Safety glasses, if included in the kit or classroom safety procedures
• Whiteboard or document camera
• Timer
• Clearly labeled component collection trays
• Paper towels or a safe storage container for disconnected batteries

Assessment

• During the demonstration, ask students to identify polarity and explain why a closed loop is required before they begin building.
• During team testing, use a checklist for safe handling, correct polarity, complete loop, productive roles, and accurate observations.
• Review the final drawing and explanation for evidence that students understand the relationship between a closed loop and device operation. Use responses to group students for the next circuit investigation.

Differentiation

• Provide a partially drawn circuit diagram, color-coded wires, and the sentence frames “The circuit is closed when…” and “The device did not work because…” for students who need additional support.
• Pair students strategically and keep roles visible; allow students to demonstrate understanding orally before recording it in writing.
• For EAL students, preview key terms with labeled component images and repeatedly model “positive terminal,” “negative terminal,” “open loop,” and “closed loop.”
• Challenge ready students to create two different circuit arrangements that produce the same result, then explain which part of the path is essential. Do not permit extra testing that creates a direct battery-terminal connection.