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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 8 · 40 questions
TalentJR

Robot tip (Teeth × turns): Teeth passing = driver teeth × driver turns. Driven turns = teeth passing ÷ driven teeth. Gear ratio = driven teeth ÷ driver teeth (a ratio of 3 means 3 times slower).

NameDateTime takenScore ___ / 40
  1. 1.🔢 Gear ratio = driven teeth ÷ … (a) number of gears (b) motor volts (c) wheel size (d) driver teeth
  2. 2.⚙️ An 8-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  3. 3.⚙️ A motor makes 80 turns a minute with an 8-tooth gear on it. That gear drives a 16-tooth gear. How many turns a minute does the 16-tooth gear make?
  4. 4.⚙️ A 10-tooth gear drives a 20-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  5. 5.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times bigger (b) 3 times faster (c) 3 times louder (d) 3 times slower
  6. 6.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driver turns 21 times. How many times does the driven gear turn?
  7. 7.⚙️ A motor makes 200 turns a minute with an 8-tooth gear on it. That gear drives a 40-tooth gear. How many turns a minute does the 40-tooth gear make?
  8. 8.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  9. 9.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driver turns 32 times. How many times does the driven gear turn?
  10. 10.⚙️ A 30-tooth driver gear turns a 15-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  11. 11.⚙️ A 12-tooth gear drives a 48-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  12. 12.⚙️ A motor makes 210 turns a minute with a 15-tooth gear on it. That gear drives a 45-tooth gear. How many turns a minute does the 45-tooth gear make?
  13. 13.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  14. 14.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  15. 15.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driver turns 21 times. How many times does the driven gear turn?
  16. 16.⚙️ A 36-tooth driver gear turns a 12-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  17. 17.⚙️ A motor makes 210 turns a minute with an 8-tooth gear on it. That gear drives a 24-tooth gear. How many turns a minute does the 24-tooth gear make?
  18. 18.⚙️ A 60-tooth driver gear turns a 12-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  19. 19.⚙️ A 36-tooth driver gear turns a 12-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  20. 20.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driver turns 24 times. How many times does the driven gear turn?
  21. 21.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driver turns 28 times. How many times does the driven gear turn?
  22. 22.⚙️ A motor makes 240 turns a minute with an 8-tooth gear on it. That gear drives a 32-tooth gear. How many turns a minute does the 32-tooth gear make?
  23. 23.⚙️ A motor makes 280 turns a minute with a 12-tooth gear on it. That gear drives a 48-tooth gear. How many turns a minute does the 48-tooth gear make?
  24. 24.⚙️ An 80-tooth driver gear turns a 20-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  25. 25.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) zero (b) small (fast, weak) (c) big (slow and strong) (d) never important
  26. 26.⚙️ A motor makes 400 turns a minute with a 10-tooth gear on it. That gear drives a 50-tooth gear. How many turns a minute does the 50-tooth gear make?
  27. 27.⚙️ A 45-tooth driver gear turns a 15-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  28. 28.⚙️ A motor makes 240 turns a minute with a 10-tooth gear on it. That gear drives a 20-tooth gear. How many turns a minute does the 20-tooth gear make?
  29. 29.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driver turns 15 times. How many times does the driven gear turn?
  30. 30.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  31. 31.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driver turns 24 times. How many times does the driven gear turn?
  32. 32.⚙️ A 32-tooth driver gear turns an 8-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  33. 33.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  34. 34.⚙️ A motor makes 120 turns a minute with a 20-tooth gear on it. That gear drives an 80-tooth gear. How many turns a minute does the 80-tooth gear make?
  35. 35.⚙️ A motor makes 500 turns a minute with a 12-tooth gear on it. That gear drives a 60-tooth gear. How many turns a minute does the 60-tooth gear make?
  36. 36.⚙️ A motor makes 30 turns a minute with an 8-tooth gear on it. That gear drives a 24-tooth gear. How many turns a minute does the 24-tooth gear make?
  37. 37.⚙️ A 15-tooth gear drives a 75-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  38. 38.⚙️ A 60-tooth driver gear turns a 12-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  39. 39.⚙️ A motor makes 250 turns a minute with a 15-tooth gear on it. That gear drives a 75-tooth gear. How many turns a minute does the 75-tooth gear make?
  40. 40.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driver turns 40 times. How many times does the driven gear turn?

Answer key

  1. driver teeth
  2. 24
  3. 40
  4. 2
  5. 3 times slower
  6. 7
  7. 40
  8. 21
  9. 8
  10. 12
  11. 4
  12. 70
  13. 4
  14. 20
  15. 7
  16. 9
  17. 70
  18. 30
  19. 18
  20. 8
  21. 7
  22. 60
  23. 70
  24. 40
  25. big (slow and strong)
  26. 80
  27. 27
  28. 120
  29. 5
  30. 27
  31. 8
  32. 40
  33. 3
  34. 30
  35. 100
  36. 10
  37. 5
  38. 45
  39. 50
  40. 10

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