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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 204 · 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 gear drives an 80-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  2. 2.🔢 Gear ratio = driven teeth ÷ … (a) driver teeth (b) wheel size (c) motor volts (d) number of gears
  3. 3.⚙️ A motor makes 200 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?
  4. 4.⚙️ A motor makes 400 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?
  5. 5.⚙️ A 45-tooth driver gear turns a 15-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  6. 6.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  7. 7.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) small (fast, weak) (b) big (slow and strong) (c) zero (d) never important
  8. 8.⚙️ A 10-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  9. 9.⚙️ A motor makes 320 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?
  10. 10.⚙️ A motor makes 180 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?
  11. 11.⚙️ A 20-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  12. 12.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times faster (b) 3 times bigger (c) 3 times louder (d) 3 times slower
  13. 13.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driver turns 15 times. How many times does the driven gear turn?
  14. 14.⚙️ A 20-tooth gear drives a 100-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  15. 15.⚙️ A 15-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  16. 16.⚙️ A 10-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  17. 17.⚙️ A 12-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  18. 18.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  19. 19.⚙️ A motor makes 240 turns a minute with a 12-tooth gear on it. That gear drives a 24-tooth gear. How many turns a minute does the 24-tooth gear make?
  20. 20.⚙️ An 8-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  21. 21.⚙️ A 12-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  22. 22.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  23. 23.⚙️ A 12-tooth driver gear turns a 60-tooth driven gear. The driver turns 50 times. How many times does the driven gear turn?
  24. 24.⚙️ A motor makes 240 turns a minute with a 20-tooth gear on it. That gear drives a 40-tooth gear. How many turns a minute does the 40-tooth gear make?
  25. 25.⚙️ A motor makes 210 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?
  26. 26.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  27. 27.⚙️ A 15-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  28. 28.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  29. 29.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  30. 30.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  31. 31.⚙️ A motor makes 20 turns a minute with a 20-tooth gear on it. That gear drives a 40-tooth gear. How many turns a minute does the 40-tooth gear make?
  32. 32.⚙️ A 12-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  33. 33.⚙️ A 12-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  34. 34.⚙️ A 16-tooth driver gear turns an 8-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  35. 35.⚙️ A 10-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  36. 36.⚙️ An 8-tooth gear drives a 16-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  37. 37.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  38. 38.⚙️ A 12-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  39. 39.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  40. 40.⚙️ A 60-tooth driver gear turns a 20-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?

Answer key

  1. 4
  2. driver teeth
  3. 100
  4. 80
  5. 27
  6. 21
  7. big (slow and strong)
  8. 30
  9. 80
  10. 60
  11. 3
  12. 3 times slower
  13. 5
  14. 5
  15. 45
  16. 4
  17. 2
  18. 36
  19. 120
  20. 16
  21. 48
  22. 8
  23. 10
  24. 120
  25. 70
  26. 6
  27. 4
  28. 12
  29. 30
  30. 4
  31. 10
  32. 24
  33. 36
  34. 6
  35. 3
  36. 2
  37. 18
  38. 5
  39. 27
  40. 30

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