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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 65 · 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 motor makes 30 turns a minute with a 12-tooth gear on it. That gear drives a 36-tooth gear. How many turns a minute does the 36-tooth gear make?
  2. 2.⚙️ A 12-tooth gear drives a 36-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  3. 3.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times bigger (b) 3 times slower (c) 3 times faster (d) 3 times louder
  4. 4.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  5. 5.⚙️ A motor makes 450 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?
  6. 6.⚙️ A 30-tooth driver gear turns a 15-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  7. 7.⚙️ A motor makes 140 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?
  8. 8.🔢 Gear ratio = driven teeth ÷ … (a) motor volts (b) driver teeth (c) number of gears (d) wheel size
  9. 9.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  10. 10.⚙️ A 36-tooth driver gear turns a 12-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  11. 11.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  12. 12.⚙️ An 8-tooth gear drives a 16-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  13. 13.⚙️ A 50-tooth driver gear turns a 10-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  14. 14.⚙️ A 12-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  15. 15.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  16. 16.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) zero (b) never important (c) small (fast, weak) (d) big (slow and strong)
  17. 17.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  18. 18.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driver turns 40 times. How many times does the driven gear turn?
  19. 19.⚙️ A 10-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  20. 20.⚙️ A motor makes 330 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?
  21. 21.⚙️ A 20-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  22. 22.⚙️ A 60-tooth driver gear turns a 15-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  23. 23.⚙️ A 75-tooth driver gear turns a 15-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  24. 24.⚙️ A 15-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  25. 25.⚙️ A 10-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  26. 26.⚙️ A 12-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  27. 27.⚙️ A 15-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  28. 28.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  29. 29.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  30. 30.⚙️ A 10-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  31. 31.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  32. 32.⚙️ An 8-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  33. 33.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  34. 34.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  35. 35.⚙️ A 10-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  36. 36.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  37. 37.⚙️ A motor makes 60 turns a minute with a 10-tooth gear on it. That gear drives a 30-tooth gear. How many turns a minute does the 30-tooth gear make?
  38. 38.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  39. 39.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  40. 40.⚙️ A motor makes 100 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?

Answer key

  1. 10
  2. 3
  3. 3 times slower
  4. 27
  5. 90
  6. 8
  7. 70
  8. driver teeth
  9. 4
  10. 30
  11. 8
  12. 2
  13. 35
  14. 2
  15. 16
  16. big (slow and strong)
  17. 18
  18. 8
  19. 3
  20. 110
  21. 100
  22. 28
  23. 30
  24. 2
  25. 4
  26. 36
  27. 75
  28. 4
  29. 9
  30. 50
  31. 4
  32. 40
  33. 16
  34. 5
  35. 20
  36. 6
  37. 20
  38. 10
  39. 6
  40. 20

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