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When a wheel makes one full turn, the robot rolls forward by the wheel’s circumference — the distance round its edge. Circumference = π × diameter. With wheels of 7, 14, 21 … cm, π = 22/7 makes the sum easy: a 14 cm wheel has a circumference of 22/7 × 14 = 44 cm. Five turns roll 44 × 5 = 220 cm. With π = 3.14, a 10 cm wheel rolls 31.4 cm each turn. To find the turns needed, divide the distance by the circumference.
✓ You passed this lesson’s test.
Circumference × turns — “distance = π × diameter × number of turns”
Use it for: Programming a robot to drive an exact distance, circle lessons in maths and robotics competitions.
Work it out in your head or on paper, type the answer and press Check. Stuck? Press “Show me how”.
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20 questions. Check each answer, then go to the next one. Get 16 or more right to pass.
🏅 Sign in with Google to earn the 📏 Wheel Roller badge when you pass — and a certificate when you finish all 10 lessons of Part 2 · How robots move and sense. You can still take the test without signing in.
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