Inputs Outputs Basics

Overview

Students explore how micro:bit systems use inputs (sensors) and outputs (LEDs, sound) to respond to the real world. They connect this idea to number relationships on a number line by using positive/negative values to represent “above/below,” so they can explain how outputs change with inputs.

Learning intentions

Students will be able to:

• Classify common devices as inputs or outputs in a micro:bit context.
• Explain what the number “0” means in a sensor reading situation (neutral point).
• Use positive and negative numbers to describe opposite directions or states (e.g., temperature above/below).
• Interpret inequality statements as relative positions on a number line when reasoning about sensor thresholds.

Success criteria

• I can sort at least 8 scenario cards into correct input/output categories.
• I can explain how a sensor reading of 0 and positive/negative values affect what the micro:bit displays or plays.
• I can use a number line to interpret statements like “-3 > -7” as “-3 is to the right of -7.”
• I can connect my prediction (output behavior) to a specific input value.

Curriculum links

• The Number System — Understand that positive and negative numbers are used together to describe opposite directions/values and explain the meaning of 0.
• The Number System — Interpret statements of inequality as statements about relative position on a number line diagram.
• Micro:bit / engineering design (practice) — Communicate how inputs drive outputs in a system.

Lesson structure (45 minutes)

1. 0–5 min · Hook (system detective). Teacher shows two quick prompts: “A button press causes the micro:bit to flash” and “A microphone records sound.” Students quickly identify what they think are inputs vs outputs using thumbs-up/down and one-word answers.

2. 5–12 min · Direct teach (inputs vs outputs + sign meaning). Teacher explains: an input tells the micro:bit what’s happening; an output shows what the micro:bit does next. Teacher adds a real-world example using sign: temperature can be above or below zero, elevation can be above or below sea level, or balance/charge can be positive/negative. Students take notes using a 2-column chart: “Input” and “Output,” then add a third note: “0 = neutral point.”

3. 12–22 min · Hands-on stations (classifying devices). Teacher divides the class into 4 stations (about 5 students each).

• Station A: Card sort—students match devices/scenarios to input/output and justify with a sentence stem.
• Station B: Sensor demo—students watch a sensor reading change (e.g., light or temperature if available) and predict whether values should be “above/below 0” in the story context.
• Station C: Output demo—students test outputs (LED pattern or sound) and record which input change triggers which output change.
• Station D: Number line thresholds—students place two numbers on a small number line and decide which threshold is “greater” (using inequality interpretation). Students rotate every 2–3 minutes; teacher circulates with a quick checklist.

4. 22–32 min · Whole-class synthesis (from numbers to behavior). Teacher writes two example “sensor stories” on the board:

• “The temperature is -5°C. The micro:bit turns on a warming message if it’s below -3°C.”
• “The temperature is +2°C. The micro:bit turns on a cooling message if it’s above +1°C.” Teacher asks students to interpret the inequality and describe where the number sits on the number line (right/left of 0 and relative to the threshold). Students use quick “claim-evidence” responses: claim output should/shouldn’t happen, evidence based on comparing numbers.

5. 32–42 min · Micro:bit mini-challenge (pairs). Teacher gives each pair one scenario template: “When input ___ changes, the output should ___.” Students design a simple behavior plan using one input (button, light, temperature, motion, microphone) and one output (LED, sound). Students must include:

• What the input value represents (and whether it’s above/below a neutral point).
• One inequality comparison they would use (described in words, then shown with symbols). Teacher collects 5 sample plans to read aloud.

6. 42–45 min · Exit ticket (check for mastery). Students complete a quick 4-part exit ticket:

• Circle input or output for 4 devices/scenarios.
• Write what 0 means in one sensor story.
• Choose which number is greater on a number line: -3 or -7 (and justify with “to the right/to the left”).
• One sentence: “If input ___ is ___ than threshold, output ___ should happen.”

Resources

• micro:bit kits (or class set) with compatible cables
• sample micro:bit code preloaded for basic LED/sound output and a sensor readout
• device scenario cards (input/output)
• small number line printouts labeled with negative to positive values
• station rotation timers
• student data sheets (2-column input/output + one inequality threshold box)
• exit ticket slips or digital form (no links)

Assessment

• Formative: station teacher checklist (correct classification + justification sentence)
• Formative: whole-class responses during the sensor threshold discussion (inequality and number line reasoning)
• Exit ticket: accuracy on input/output sorting, meaning of 0, and inequality/relative position

Differentiation

• Provide ELL-friendly visual aids: icons for sensors (input) vs icons for LEDs/speakers (output) and sentence starters (“An input is… because…,” “An output is…”).
• Offer a partially completed number line for students who need structure; they just place and compare two labeled points.
• Provide an “if/then” word bank for the micro:bit mini-challenge (if input is above…, then output is…).
• Extension for early finishers: add a second condition (“If temperature is below -3 AND light is low, then output plays a sound pattern.”).