Sensor Basics

Overview

Students explore what sensors do in real-world technology by focusing on a temperature sensor on the Micro:bit. They connect readings above and below zero to positive and negative rational numbers and interpret temperature data using number-line thinking.

Learning intentions

Students will be able to:

• Explain, in their own words, how a sensor turns a physical quantity into data.
• Read temperature values from the Micro:bit and record them accurately.
• Represent temperature changes using positive and negative numbers and explain what 0 means.
• Use coordinate ideas (same x or same y) to reason about distances between readings.

Success criteria

• I can describe a sensor as a device that measures and outputs data.
• I can display and record temperature values from the Micro:bit.
• I can write the meaning of 0 in the temperature situation and explain values above vs. below 0.
• I can interpret and compare temperature readings using rational numbers.

Curriculum links

• Number System — understand positive and negative numbers for real-world quantities with opposite directions/values, and explain the meaning of 0 in each situation (temperature above/below zero).
• Number System — write, interpret, and explain order of rational numbers in real-world contexts (warmer/colder statements).
• Number System — absolute value as distance from 0, interpreted as magnitude for a positive or negative quantity (e.g., debt example applied to temperature magnitude).
• Number System — solve real-world and mathematical problems by graphing points in all four quadrants and use coordinates/absolute value to find distances with shared x or y.

Lesson structure (45 minutes)

1. 0–5 min · Hook (Real tech). Teacher shows two quick temperature examples (warm vs. freezing) and asks: “How does a device know how warm or cold it is?” Students turn-and-talk, then share one idea about how technology measures temperature.

2. 5–12 min · Mini direct teach (Sensor → data). Teacher demonstrates the Micro:bit temperature sensor briefly and shows where the value appears on-screen (or on a connected display). Students sketch a simple “sensor → number” diagram: “temperature in” becomes “temperature value out.”

3. 12–20 min · Guided setup (Make it work). Teacher models uploading the temperature display program and shows how values update. Students follow along: pair-check that the Micro:bit displays temperature and they can see numbers changing when they warm the device with their hands.

4. 20–30 min · Temperature data collection (Hands-on). Teacher assigns each pair a short sequence: measure 3 times (baseline near room temp, warmed, and cooled if possible using a safe method like stepping away from warm hands). Students record three readings in a table and circle the value closest to 0; teacher prompts them to label “above 0” or “below 0” where relevant.

5. 30–38 min · Rational number reasoning (Order + magnitude). Teacher writes two of the students’ recorded temperatures on the board (include at least one negative example if possible). Students answer two quick prompts: (a) “Which is warmer, A or B?” and (b) “What is the distance from 0 for each?” using absolute value language (“magnitude,” “distance from zero”).

6. 38–44 min · Coordinate quick-check (Distance meaning). Teacher draws a simple graph with points representing two readings using coordinates where one axis represents a consistent index (for example, Reading # on x-axis and temperature on y-axis), then asks for the distance between the points with the same x or same y. Students explain verbally or in writing how absolute value matches the distance on the graph when one coordinate is the same.

7. 44–45 min · Exit ticket (Quick proof). Teacher collects a short response: “Write two temperature values from your table, state which is warmer, and write what 0 means in this context.” Students submit on paper or in a shared form.

Resources

• Micro:bit devices (one per pair) with temperature sensor access
• Computer with Micro:bit programming environment open (teacher and student login ready)
• Data recording sheet (table with 3–4 rows, columns for reading, above/below 0, and absolute value)
• Blank coordinate-grid worksheet or printed quick graph template
• Markers/pencils and board/markers for teacher visuals
• Optional: classroom warm/cool stations (e.g., hand-warmed baseline; room temperature; safe cooling plan)
• Timer for measurement sequence

Assessment

• Teacher circulates during setup and data collection to check values are displayed and recorded correctly (accuracy + procedure).
• Formative checks during the “warmer/colder” prompts: listen for correct order of rational numbers and correct interpretation of 0.
• Exit ticket: verifies students can connect sensor readings to rational numbers, explain 0, and compare two temperatures.

Differentiation

• Support: Provide a guided worksheet with sentence starters such as “The warmer temperature is ___ because ___.” and “0°C means ___. Values below 0 are __.”
• Support: Offer a worked example on the board with absolute value phrasing (“| -5 | = 5 means the magnitude is 5 degrees from zero”).
• Extension: Challenge advanced pairs to predict the next reading after warming/cooling and justify using order and absolute value.
• EAL/SEN: Allow oral responses for the warmer/colder part first, then require a short written version; provide number-line visuals showing negative left of 0.