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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 43 · 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 15-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  2. 2.⚙️ An 8-tooth gear drives a 32-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  3. 3.🔢 Gear ratio = driven teeth ÷ … (a) driver teeth (b) number of gears (c) motor volts (d) wheel size
  4. 4.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) big (slow and strong) (b) never important (c) zero (d) small (fast, weak)
  5. 5.⚙️ A 15-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  6. 6.🔢 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
  7. 7.⚙️ A 10-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  8. 8.⚙️ An 8-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  9. 9.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driver turns 21 times. How many times does the driven gear turn?
  10. 10.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driver turns 32 times. How many times does the driven gear turn?
  11. 11.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  12. 12.⚙️ A motor makes 200 turns a minute with a 15-tooth gear on it. That gear drives a 60-tooth gear. How many turns a minute does the 60-tooth gear make?
  13. 13.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  14. 14.⚙️ A 45-tooth driver gear turns a 15-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  15. 15.⚙️ A 10-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  16. 16.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  17. 17.⚙️ A 20-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  18. 18.⚙️ A 15-tooth gear drives a 75-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  19. 19.⚙️ A motor makes 80 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?
  20. 20.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 32 times. How many times does the driven gear turn?
  21. 21.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  22. 22.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  23. 23.⚙️ A motor makes 270 turns a minute with a 20-tooth gear on it. That gear drives a 60-tooth gear. How many turns a minute does the 60-tooth gear make?
  24. 24.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driver turns 30 times. How many times does the driven gear turn?
  25. 25.⚙️ A 60-tooth driver gear turns a 15-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  26. 26.⚙️ A 15-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  27. 27.⚙️ An 8-tooth gear drives a 16-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  28. 28.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driver turns 24 times. How many times does the driven gear turn?
  29. 29.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  30. 30.⚙️ A 60-tooth driver gear turns a 20-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  31. 31.⚙️ A 12-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  32. 32.⚙️ A motor makes 240 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?
  33. 33.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  34. 34.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  35. 35.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 25 times. How many times does the driven gear turn?
  36. 36.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  37. 37.⚙️ A motor makes 80 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?
  38. 38.⚙️ A motor makes 320 turns a minute with a 15-tooth gear on it. That gear drives a 60-tooth gear. How many turns a minute does the 60-tooth gear make?
  39. 39.⚙️ A 15-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  40. 40.⚙️ A 15-tooth gear drives a 45-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?

Answer key

  1. 30
  2. 4
  3. driver teeth
  4. big (slow and strong)
  5. 75
  6. 3 times slower
  7. 40
  8. 5
  9. 7
  10. 8
  11. 36
  12. 50
  13. 10
  14. 6
  15. 20
  16. 6
  17. 80
  18. 5
  19. 40
  20. 8
  21. 8
  22. 8
  23. 90
  24. 10
  25. 28
  26. 60
  27. 2
  28. 6
  29. 32
  30. 6
  31. 40
  32. 60
  33. 9
  34. 20
  35. 5
  36. 15
  37. 40
  38. 80
  39. 4
  40. 3

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