Coordinate Code

Overview

In this lesson, students connect math reasoning about signs and quadrants to a Micro:bit game control system. They will update an existing game so compass headings and button combinations move a character or select options, then justify why the movement is correct using coordinates and distance ideas.

Learning intentions

• Students will be able to represent real-world directions and opposite movements using positive and negative values.
• Students will be able to describe and interpret locations on a coordinate plane (all four quadrants) using ordered pairs.
• Students will be able to use coordinate changes and absolute value to reason about horizontal/vertical distance.
• Students will be able to modify a Micro:bit game so compass/button inputs correctly map to coordinate-based movement.

Success criteria

• I can explain what 0 means in a direction-based situation (for example, “no movement east/west” or “on the x-axis”).
• I can state the quadrant and ordered pair for a point and describe the reflection relationship when signs change.
• I can use absolute value to find distance between points that share an x-coordinate or a y-coordinate.
• I can modify my Micro:bit game so pressing buttons and turning with a compass changes my character’s position in a way that matches my coordinate rules.

Curriculum links

• The Number System — positive/negative numbers in real-world contexts and explaining 0 (6.NS.C.5).
• The Number System — signs in ordered pairs and reflections across axes (6.NS.C.6b).
• The Number System — interpret inequality on a number line (optional quick check: 6.NS.C.7a).
• The Number System — graphing points in all four quadrants; use coordinates and absolute value for distance (6.NS.C.8).

Lesson structure (45 minutes)

1. 0–5 min · Hook (Compass vs Buttons). Teacher shows two prompts: “Press A to move left” and “Turn so the compass points east to move right,” then asks students to predict direction changes using arrows. Students quickly sketch a “left/right” sign rule (negative/positive) and share one prediction.

2. 5–12 min · Mini direct teach (Quadrants with signs). Teacher draws a simple coordinate plane and labels x-axis (East/West) and y-axis (North/South), emphasizing ordered pairs like (x, y), quadrants, and what 0 represents on each axis. Students complete a 4-point warmup: “If x is positive and y is negative, which quadrant?” and record one ordered pair with correct signs.

3. 12–20 min · Input mapping demo (Micro:bit logic connection). Teacher explains the game rule the class will use: the character position is stored as (x, y); button presses add/subtract from x or y, and compass headings choose which direction to move. Students watch and then tell which variable changes when they press Button A, Button B, or move compass past two thresholds (example: near 0°/90°/180°/270°).

4. 20–33 min · Build/modify: Compass + button combinations. Teacher releases students to modify their starter program with a small checklist: (1) update x and y using button combos, (2) add compass-based direction choice, (3) keep positions within a simple grid limit, and (4) ensure opposite directions use opposite signs. Students work in pairs: test repeatedly, record one successful input-output example in their notebook, and note any sign mistakes.

5. 33–40 min · Math justification check (Distance & quadrant reasoning). Teacher gives a “move from (x1, y1) to (x2, y2)” card where either x matches or y matches, then asks students to compute distance using absolute value and identify the quadrant of the new point. Students complete one card and write a sentence: “Because the x values are the same, the distance is ___; the sign of y determines the quadrant.”

6. 40–45 min · Exit ticket (Game correctness + one coordinate claim). Teacher collects a quick prompt: “Describe how your game changes x and y when Button A+B is pressed, and name the quadrant for a given ordered pair from your tests.” Students submit answers showing both input rule and coordinate interpretation.

Resources

• Micro:bit devices (one per pair if possible)
• Starter game project (grid-based position using x,y)
• Compass sensor block/driver setup instructions
• Printed coordinate plane handout (quadrants labeled)
• Student notebooks or lab journals
• “Move card” printouts (distance using absolute value)
• Timer (visual) to manage building/testing time
• Optional: projector screen with example code snippets

Assessment

• Teacher circulates during building to check students correctly use sign rules (positive/negative) for opposite directions.
• During the quadrant/warmup and the card activity, teacher checks ordered pair signs and quadrant identification.
• Exit ticket: students must explain an input-to-coordinate rule and correctly identify a quadrant for at least one ordered pair.

Differentiation

• Support: Provide a “sign starter table” (East=+, West=-, North=+, South=-) and sentence starters: “When x decreases, the point moves left, meaning x is negative.”
• Support: Offer a scaffolded checklist for code edits (buttons first, compass thresholds second, then coordinate display/verification).
• Extension: Challenge students to use two compass thresholds (e.g., “heading between 0°–45° moves East, 45°–135° moves North”) and predict the resulting quadrant before testing.
• EAL/SEN: Allow students to draw the before/after point on the coordinate plane and use key terms “left/right,” “up/down,” “quadrant,” and “ordered pair” with word banks.

Extension

• Students create a new “combo” control (two buttons + compass) and write a one-paragraph rule connecting: input → sign change → ordered pair → quadrant.