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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 12 · 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.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  2. 2.⚙️ A 60-tooth driver gear turns a 20-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  3. 3.🔢 Gear ratio = driven teeth ÷ … (a) number of gears (b) motor volts (c) driver teeth (d) wheel size
  4. 4.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 28 times. How many times does the driven gear turn?
  5. 5.⚙️ A motor makes 140 turns a minute with a 15-tooth gear on it. That gear drives a 30-tooth gear. How many turns a minute does the 30-tooth gear make?
  6. 6.⚙️ A 60-tooth driver gear turns a 15-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  7. 7.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  8. 8.⚙️ A 10-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  9. 9.⚙️ A 20-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  10. 10.⚙️ A 30-tooth driver gear turns a 10-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  11. 11.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 14 times. How many times does the driven gear turn?
  12. 12.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times faster (b) 3 times louder (c) 3 times bigger (d) 3 times slower
  13. 13.⚙️ A 50-tooth driver gear turns a 10-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  14. 14.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) small (fast, weak) (b) big (slow and strong) (c) never important (d) zero
  15. 15.⚙️ A motor makes 60 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?
  16. 16.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  17. 17.⚙️ A 15-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  18. 18.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 40 times. How many times does the driven gear turn?
  19. 19.⚙️ A 48-tooth driver gear turns a 12-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  20. 20.⚙️ An 8-tooth gear drives a 16-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  21. 21.⚙️ A motor makes 280 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?
  22. 22.⚙️ A 20-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  23. 23.⚙️ A 20-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  24. 24.⚙️ An 8-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  25. 25.⚙️ A 30-tooth driver gear turns a 15-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  26. 26.⚙️ A 16-tooth driver gear turns an 8-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  27. 27.⚙️ A 32-tooth driver gear turns an 8-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  28. 28.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  29. 29.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  30. 30.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  31. 31.⚙️ A 100-tooth driver gear turns a 20-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  32. 32.⚙️ An 80-tooth driver gear turns a 20-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  33. 33.⚙️ A 12-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  34. 34.⚙️ A 20-tooth gear drives a 100-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  35. 35.⚙️ A 10-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  36. 36.⚙️ A motor makes 100 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?
  37. 37.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  38. 38.⚙️ A 12-tooth driver gear turns a 60-tooth driven gear. The driver turns 35 times. How many times does the driven gear turn?
  39. 39.⚙️ A motor makes 600 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?
  40. 40.⚙️ A motor makes 360 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?

Answer key

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

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