Tele-Potato Base Build

Overview

Students launch Tele-Potato: a wireless “hot potato” game using Micro:bits, radio communication, and a countdown timer. They build the base MakeCode version in pairs and connect gameplay rules (fairness, fun, replayable) to clear computational logic.

Learning intentions

• Students will be able to describe opposite quantities and additive inverses as they apply to “state” changes in the game logic (potato in/out, decrementing time).
• Students will be able to interpret a subtraction situation as adding an additive inverse in order to reason about countdown and reset behaviors.
• Students will be able to divide integers and interpret quotients as rational values when reasoning about timing intervals and scaling rules (e.g., “every N ticks”).
• Students will be able to use radio send/receive and a countdown timer to coordinate gameplay between two devices.

Success criteria

• I can explain how the game uses radio signals to decide who has the potato.
• I can implement a countdown timer that resets correctly and ends the round.
• I can predict what happens when I change a timer value and justify the effect using number-line ideas (positive/negative direction).
• I can test and debug my program until the game works fairly for both players.

Curriculum links

• The Number System: additive inverses and interpreting signed changes in contexts (CCSS.MATH.CONTENT.7.NS.A.1b and CCSS.MATH.CONTENT.7.NS.A.1c).
• The Number System: subtraction as adding the additive inverse; use this to reason about countdown/reset behavior (CCSS.MATH.CONTENT.7.NS.A.1c).
• The Number System: multiplication/division reasoning with signed numbers and interpreting quotients in real contexts (CCSS.MATH.CONTENT.7.NS.A.2a and CCSS.MATH.CONTENT.7.NS.A.2b).
• The Number System: modeling opposite quantities combining to make 0 (CCSS.MATH.CONTENT.7.NS.A.1a).

Lesson structure (45 minutes total)

1. 0–5 min · Hook: “Fair hot potato?” Teacher shows two scenarios on the board: (A) timer only starts for one player, (B) both players share a consistent countdown. Students quick-write: Which seems fair and why? Students discuss pairwise and identify what “fair” must mean in code.

2. 5–12 min · Mini-lesson: numbers that move Teacher explains the idea of a countdown as “adding the inverse” (subtracting time is adding a negative change) and models on a number line from 10 down to 0. Students complete a 2-item check: “If time decreases by 3 from 8, what is the result?” and “Explain it using ‘adding the opposite’ language.”

3. 12–20 min · Demo: Radio + timer overview Teacher runs the Tele-Potato base code once: how radio send/receive passes the potato, and how the timer controls round length. Students follow along with a “Think–Predict–Watch” chart: What should Player A do? What should Player B do? What did we actually observe?

4. 20–33 min · Pair build: MakeCode Tele-Potato (base version) Teacher gives pairs a short build checklist (connect Micro:bit, open project, upload base code, confirm radio setup and timer blocks). Students build the base version in MakeCode using the provided Tele-Potato project blocks: radio send, radio receive, and the countdown timer. They run it on two Micro:bits and confirm the potato can pass and the round ends.

5. 33–39 min · Debug sprint: test, fix, and justify Teacher sets a 6-minute timer and provides common issues: radio not talking (wrong channel), timer not resetting, potato not passing reliably. Students use a “Bug Log” template: Problem → Evidence (what happens) → Change (what they did) → Expected effect (in numbers/state).

6. 39–45 min · Exit ticket: math meaning + game fairness Teacher asks each student to answer two prompts:

• “In the countdown, explain subtraction as adding an additive inverse.” (Example: writing a negative change)
• “If the round time is changed, predict what changes in the game and why.” Students submit individually; teacher collects for quick review.

Resources

• 25 Micro:bits (or shared station set), batteries/USB connections
• Laptops/desktops with MakeCode for micro:bit available
• Printed or on-screen Tele-Potato base build checklist (radio send/receive, countdown timer blocks)
• Pair roles cards (Driver, Navigator)
• “Bug Log” printable
• Exit ticket slips or digital form
• Number-line handout for quick inverse/additive-inverse reminder

Assessment

• Formative checks during hook discussion: students identify fairness requirements in plain language.
• Build verification: teacher observes whether each pair can run a working base game on two Micro:bits.
• Bug Log review: students explain changes with clear cause-and-effect (not just “it works now”).
• Exit ticket: demonstrates understanding of additive inverse/subtraction reasoning tied to countdown behavior.

Differentiation

• Support: Provide sentence starters for the exit ticket (e.g., “Subtracting time means adding the opposite.” “A decrease is a negative change on the number line.”).
• Support: Give pairs a labeled diagram of the base code flow (radio receive → potato state → timer decrement → round end/reset).
• Challenge: After base works, ask pairs to propose one “fairness tweak” (e.g., how long the timer should last, or how resets should occur) and predict the math effect before testing.
• EAL/SEN: Allow drawing the number-line thinking; accept explanations using words plus a single calculation.