Sense the World

Sessions

1. Session 1 · 60 min

   What number does the light sensor give?

   The “light level” block gives a number from 0 (dark) to 255 (bright); “show number” shows it on the display. In the simulator the value is set by hand with its sensor control: it is not a measurement.

   The adult says first: “A sensor turns the world into a number. Let's find how small and how big it gets.”

   Learner card

   1. Put “light level” in “show number”.
   2. Put them in “forever”.
   3. Make the simulator dark.
   4. Guess the number. Check.
   5. Now make it bright.

   Key words (show each with a picture): sensor · number · light level

   Timing (25 of 60 min at the screen)

   1. 15 minAway from the screen: Light hunt: walk round the room with picture cards, put places in order from darkest to brightest, and guess a number from 0 to 255 for each.
   2. 15 minAt the screen: MakeCode: “light level” in “show number” in “forever”; the adult sets the simulator's light level with the arrow keys; read each number.
   3. 10 minAway from the screen: Compare the room guesses with the simulator's numbers: who chose them?
   4. 10 minAt the screen: Guess the smallest and largest numbers, then check both ends in the simulator.
   5. 10 minAway from the screen: Fill in the table; say why the simulator's number was set by hand.

   In the studio

   No studio lab or activity.

   Outside the studio: MakeCode editor and its micro:bit simulator (makecode.microbit.org)

   Hands-on

   Nothing is powered: this session uses the simulator only. First, away from the screen, the group hunts for light around the room with picture cards, puts places in order from darkest to brightest and guesses a number from 0 to 255 for each. Then the learner puts “light level” inside “show number”, inside “forever”. To set the light level, the adult clicks the simulator's light circle, then presses the arrow keys (each press changes it by 1) and checks the number shown beside it: dark, the middle and bright, reading the number each time. The adult asks: who chose that number, the micro:bit or you? Then the learner predicts the smallest and the largest number the block can give, and checks both ends (the Home and End keys jump straight to 0 and 255).

   Starting blocks: Built from scratch: “forever” holding “show number”, with “light level” inside it.

   Evidence to collect

   A prediction for each setting, a short test table (Simulator setting | My guess | Number shown) for dark, middle and bright, and the learner's spoken explanation that the simulator's number was set by hand, not measured.

   Test table columns: Simulator setting | My guess | Number shown

   Predict

   Before each setting, the learner guesses the number: near 0, near the middle, or near 255?

   Debug

   If the number never changes, check that “light level” sits inside “show number”, and both inside “forever”.

   Reflect

   Why can't the simulator tell us how bright our room is?

   Works towards: Readings with units

2. Session 2 · 75 min

   How bright is it on our table?

   Real readings: the micro:bit measures light with some of the LEDs on its screen, so the torch shines on the screen and the paper covers it. The first reading can be 0 while the sensor turns on. A fair test keeps the torch at the same height.

   The adult says first: “Now the real micro:bit measures. Paper makes it darker. Guess first.”

   Learner card

   1. Press A. Read the number.
   2. Put one sheet on top.
   3. Guess: up or down?
   4. Press A through the paper.
   5. Lift it. Read and write.
   6. Now two sheets, then three.

   Key words (show each with a picture): reading · fair test · paper

   Timing (10 of 75 min at the screen)

   1. 10 minAway from the screen: Guess: put 0 to 3 sheets in order from the brightest reading to the darkest.
   2. 10 minAt the screen: The simulator first, then plug in USB and download.
   3. 35 minAway from the screen: Real readings, torch on and off: press A through the paper, lift it, read the sliding number.
   4. 20 minAway from the screen: Fill in the table; say which reading is darkest and what was kept the same.

   In the studio

   No studio lab or activity.

   Outside the studio: MakeCode editor and its micro:bit simulator (makecode.microbit.org)

   Hands-on

   In the simulator first, the learner puts “show number” with “light level” inside “on button A pressed”. Then the learner plugs the micro:bit into USB and downloads it, unplugs USB, and the adult fits the battery pack. The micro:bit lies flat, screen up. The adult holds a battery torch at the 30 cm mark of a ruler standing beside it, shining down on the screen. With 0, 1, 2 and 3 sheets of plain paper over the screen, the learner presses A through the paper, then lifts it and reads the sliding number; if the first reading is 0, they press A again. Then the torch goes off and the learner takes the same four readings.

   Starting blocks: The learner's session 1 blocks, with “on button A pressed” in place of “forever”.

   Evidence to collect

   A prediction for each reading, a short test table (Sheets of paper | My guess | Reading (0–255)) for 0 to 3 sheets with the torch on and off, and the learner's spoken explanation of which reading is the darkest and why.

   Test table columns: Sheets of paper | My guess | Reading (0–255)

   Predict

   Before each reading, the learner guesses: will one more sheet make the number go up or down?

   Debug

   If a reading is 0 in bright light, press A again: the sensor gives 0 the first time it is used.

   Reflect

   What did we keep the same, so the readings are fair?

   ⚠ Adult checks before power-on: Nothing metal touches the micro:bit or its gold pins along the bottom edge (no coins, keys, foil, metal clips or jewellery): metal across the pins can short the power. Hands holding the board are fine. The learner plugs in the USB cable, gripping the plug, while the adult watches; only the adult fits or unplugs the battery pack. Light comes from a battery torch held by the adult, never a mains lamp near a child; never shine it into anyone's eyes.

   Works towards: Readings with units

3. Session 3 · 75 min

   How warm is it, and what is the unit?

   The “temperature (°C)” block reads how hot the micro:bit's chip is, in degrees Celsius; that is usually close to the room's temperature, and the chip can warm a little when it works hard. A reading is a number and a unit.

   The adult says first: “Every reading needs a unit. For temperature, the unit is degrees Celsius.”

   Learner card

   1. Button B shows the temperature.
   2. Write the number and °C.
   3. Hold it in your hands.
   4. Guess: warmer or cooler?
   5. Check the thermometer too.

   Key words (show each with a picture): temperature · °C · unit

   Timing (15 of 75 min at the screen)

   1. 10 minAway from the screen: Feel and guess: which places feel warm or cool? Guess a number in °C for each.
   2. 15 minAt the screen: Temperature on button B in the simulator, then plug in USB and download.
   3. 35 minAway from the screen: Real readings beside the thermometer: on the table, in both hands, on a shady windowsill.
   4. 15 minAway from the screen: Fill in the table; say which reading changed most, with its unit.

   In the studio

   No studio lab or activity.

   Outside the studio: MakeCode editor and its micro:bit simulator (makecode.microbit.org)

   Hands-on

   In the simulator first, the learner puts “show number” with “temperature (°C)” inside “on button B pressed”, keeping button A's light reading. The learner plugs it into USB and downloads it; the adult fits the battery pack. The learner reads the temperature on the table beside a classroom thermometer, then after cupping the micro:bit in both hands for one minute, then after one minute on a windowsill out of the sun, not above a radiator. Each time the learner writes the number with its unit, °C, and the thermometer's reading beside it.

   Starting blocks: The learner's session 2 blocks, with a second “show number” inside “on button B pressed”.

   Evidence to collect

   A prediction for each place, a short test table (Place | My guess (°C) | micro:bit (°C) | Thermometer (°C)) for three places, and the learner's spoken or written explanation of which reading changed most and whether the micro:bit and the thermometer agree.

   Test table columns: Place | My guess (°C) | micro:bit (°C) | Thermometer (°C)

   Predict

   Before each place, the learner guesses the number in °C: warmer or cooler than on the table?

   Debug

   If the two readings differ by about the same amount each time, say so: the micro:bit reads its chip, not the air.

   Reflect

   Why do we always write the unit after the number?

   ⚠ Adult checks before power-on: Nothing metal touches the micro:bit or its gold pins along the bottom edge (no coins, keys, foil, metal clips or jewellery): metal across the pins can short the power. Hands holding the board are fine. The learner plugs in the USB cable, gripping the plug, while the adult watches; only the adult fits or unplugs the battery pack. No heaters, hot drinks or direct sun on the micro:bit: hands and a shady windowsill only, not above a radiator.

   Works towards: Readings with units

4. Session 4 · 75 min

   How do we measure movement?

   The “acceleration (mg)” block, set to strength, gives a number in milli-g (mg): a milli-g is 1/1000 of a g, and a g is the pull of Earth's gravity. Strength combines all three directions, so every still position reads about the same, about 1000 (MakeCode's page gives 1023 lying flat). Only speeding up or slowing down changes it.

   The adult says first: “Movement has a number too. Its unit is mg. Guess first.”

   Learner card

   1. Lay it flat. Press A.
   2. Write the number and mg.
   3. Stand it on its edge. Guess again.
   4. Watch the bars. Start, then stop.
   5. Never throw or drop it.

   Key words (show each with a picture): movement · mg · still

   Timing (20 of 75 min at the screen)

   1. 10 minAway from the screen: Act it out: stand still, then start and stop walking suddenly; say when you feel a push.
   2. 10 minAt the screen: Strength on button A in the simulator, then plug in USB and download.
   3. 20 minAway from the screen: Still readings: lying flat, on its edge, held still. Guess before each one.
   4. 10 minAt the screen: Change to “forever” holding “plot bar graph”, then download it.
   5. 15 minAway from the screen: The bar graph: the adult slides it steadily, then starts and stops it quickly; watch the bars.
   6. 10 minAway from the screen: Fill in the table; say why still readings are all about 1000.

   In the studio

   No studio lab or activity.

   Outside the studio: MakeCode editor and its micro:bit simulator (makecode.microbit.org)

   Hands-on

   First, away from the screen, learners stand still, then start and stop walking suddenly, and say when they feel a push. In the simulator next, the learner puts “show number” with “acceleration (mg)”, set to strength, inside “on button A pressed”, then plugs the micro:bit into USB and downloads it; the adult fits the battery pack. The learner presses A with the micro:bit lying flat and still, standing on its edge against a book, and held still in a hand. Then the program changes to “forever” holding “plot bar graph” of strength up to 2000, downloaded the same way: still, about half the bars light. The adult slides it steadily along the table, then starts and stops it quickly, while the learner watches when the bars jump. Nobody throws, drops or swings it.

   Starting blocks: Built from scratch: “on button A pressed” holding “show number”, with “acceleration (mg)” set to strength inside it; then “forever” holding “plot bar graph” of the same reading up to 2000.

   Evidence to collect

   A prediction for each test, a short test table (Test | My guess | What showed (mg)) for three still positions, a steady slide and a quick start and stop, and the learner's spoken explanation of why every still position reads about 1000 and only starting or stopping changes the reading.

   Test table columns: Test | My guess | What showed (mg)

   Predict

   Before each still position, the learner guesses: about 1000 again, or different? Before the bar graph, they guess when the bars will jump.

   Debug

   If the reading on its edge is about the same as lying flat, that is right: strength ignores which way it faces.

   Reflect

   Lying still, why isn't the reading 0?

   ⚠ Adult checks before power-on: Nothing metal touches the micro:bit or its gold pins along the bottom edge (no coins, keys, foil, metal clips or jewellery): metal across the pins can short the power. Hands holding the board are fine. The learner plugs in the USB cable, gripping the plug, while the adult watches; only the adult fits or unplugs the battery pack. The micro:bit stays on the table or in a hand: never thrown, dropped or swung by its battery lead.

   Works towards: Readings with units

5. Session 5 · 75 min

   Can my logger collect readings to compare?

   The prototype, a temperature and motion logger: button A shows the temperature (°C) and button B the movement strength (mg). One movement reading can miss a quick start or stop, so the learner takes five and keeps the biggest. The learner's paper log is the logger's memory: the micro:bit shows each reading but does not keep it.

   The adult says first: “Your logger collects readings. You keep the log.”

   Learner card

   1. Button A: temperature.
   2. Button B: movement.
   3. Guess before each place.
   4. Press B five times.
   5. Write the biggest, with mg.
   6. Which place is warmest?

   Key words (show each with a picture): logger · collect · compare

   Timing (15 of 75 min at the screen)

   1. 10 minAway from the screen: Plan three places; guess the warmest and the stillest.
   2. 15 minAt the screen: Temperature on A and movement on B in the simulator, then plug in USB and download.
   3. 35 minAway from the screen: Collect: in each place, one temperature and five movement readings; write the biggest.
   4. 15 minAway from the screen: Compare the places; say which was warmest and stillest, and how you know.

   In the studio

   No studio lab or activity.

   Outside the studio: MakeCode editor and its micro:bit simulator (makecode.microbit.org)

   Hands-on

   In the simulator first, the learner puts the two readings together: “temperature (°C)” on button A and “acceleration (mg)” (strength) on button B, each inside “show number”. The learner plugs it into USB and downloads it; the adult fits the battery pack. In three places the learner reads the temperature once and presses B five times, writing down the biggest movement reading: lying on the table, on a shady windowsill (not above a radiator), and in the adult's hands while the adult walks slowly and stops suddenly, pressing B at each stop. Then the learner compares the warmest place and the stillest place (its biggest reading closest to 1000).

   Starting blocks: The learner's own blocks from sessions 3 and 4, with movement on button B.

   Evidence to collect

   The unit's evidence: the learner collects simple readings and compares them: a prediction for each place, a short test table (Place | My guess | Temperature (°C) | Biggest movement (mg)) with a temperature and the biggest of five movement readings in each of three places, and the learner's spoken or written explanation of which place was warmest, which was stillest, and how they know.

   Test table columns: Place | My guess | Temperature (°C) | Biggest movement (mg)

   Predict

   Before each place, the learner guesses which place will be warmest and which stillest.

   Debug

   If the biggest readings in two places are about the same, take five more in each: one reading can miss a start or a stop.

   Reflect

   What could a logger that keeps its own readings do that ours cannot?

   ⚠ Adult checks before power-on: Nothing metal touches the micro:bit or its gold pins along the bottom edge (no coins, keys, foil, metal clips or jewellery): metal across the pins can short the power. Hands holding the board are fine. The learner plugs in the USB cable, gripping the plug, while the adult watches; only the adult fits or unplugs the battery pack. Walking is slow, indoors and on a clear floor, with the micro:bit held by the adult in both hands.

   Works towards: Readings with units