📋 Activity Overview

One student is the 'robot' who can only follow exact instructions. Another student must guide them from one end of the classroom to a target using only precise commands (forward 3 steps, turn right 90°…).

💡 Teacher Tip

The funniest (and most powerful) moment is when the robot walks into a wall because the instructions said 'forward 5 steps' without checking for obstacles. That frustration is the 'aha' that makes algorithmic precision stick for years.

🎯 Learning Objectives

  • ✓ Write precise, unambiguous step-by-step instructions
  • ✓ Decompose navigation into atomic commands (forward, turn, stop)
  • ✓ Debug instructions when the robot doesn't reach the target
  • ✓ Understand why computers need exact, literal instructions

🗂️ Materials Needed

Blindfold (optional) Grid mat or floor tape Instruction cards Pencil & paper Target object (book/ball) Timer

📌 Step-by-Step Instructions

Demo (5 min) — Teacher is the robot. A student says 'Go to the window.' Teacher walks into a wall. 'Your instruction wasn't precise enough! Robots do EXACTLY what you say.'
Define Commands (5 min) — Class together decides on the allowed command set: FORWARD [n] steps, TURN LEFT, TURN RIGHT, STOP. Write on board.
Write First Algorithm (8 min) — In pairs, Student A writes instructions to guide Student B (the robot) from the door to the teacher's desk using only the allowed commands.
Execute & Debug (10 min) — Student B follows instructions literally. Did the robot reach the target? Mark where it stopped. Pairs identify which step went wrong and fix it.
Increase Difficulty (8 min) — Add an obstacle (chair). Pairs rewrite their algorithm to route around it. Introduce the idea of sub-routines: 'TURN AROUND = TURN LEFT + TURN LEFT'.
Debrief (4 min) — Why was your first algorithm wrong? What does this tell us about programming? Connect to how GPS navigation works with exact coordinates.

🧠 CT Pillar Connections

Algorithmic Thinking
Every navigation command is one step in a precise algorithm. Students experience firsthand how ambiguous language fails when instructions must be executed literally.
Decomposition
The journey is broken into atomic steps — each turn and each forward movement is a sub-task. Students learn to decompose 'go to desk' into 20 precise micro-instructions.

💬 Discussion Questions

  • What is the difference between 'go forward' and 'go forward 3 steps'?
  • If you had to write an algorithm for making chai, what would step 1 be? Step 2?
  • How does a GPS app know exactly which roads to take?
  • What would happen if a computer 'guessed' what you meant instead of following exact instructions?