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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 35 · 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 turns a 45-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  2. 2.⚙️ An 80-tooth driver gear turns a 20-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  3. 3.🔢 Gear ratio = driven teeth ÷ … (a) motor volts (b) wheel size (c) number of gears (d) driver teeth
  4. 4.⚙️ A 10-tooth gear drives a 20-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  5. 5.⚙️ A 15-tooth gear drives a 75-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  6. 6.⚙️ A motor makes 500 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?
  7. 7.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  8. 8.⚙️ A 15-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  9. 9.⚙️ A 32-tooth driver gear turns an 8-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  10. 10.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  11. 11.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driver turns 21 times. How many times does the driven gear turn?
  12. 12.⚙️ A motor makes 140 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?
  13. 13.⚙️ A 75-tooth driver gear turns a 15-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  14. 14.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  15. 15.⚙️ An 8-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  16. 16.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  17. 17.⚙️ An 8-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  18. 18.🔢 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
  19. 19.⚙️ 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?
  20. 20.⚙️ A 24-tooth driver gear turns a 12-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  21. 21.⚙️ A 40-tooth driver gear turns an 8-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  22. 22.⚙️ A motor makes 100 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?
  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.🔢 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)
  25. 25.⚙️ A motor makes 400 turns a minute with a 10-tooth gear on it. That gear drives a 40-tooth gear. How many turns a minute does the 40-tooth gear make?
  26. 26.⚙️ A 15-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  27. 27.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  28. 28.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  29. 29.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  30. 30.⚙️ A 100-tooth driver gear turns a 20-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  31. 31.⚙️ A motor makes 60 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?
  32. 32.⚙️ A 100-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 15-tooth driver gear turns a 75-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  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 15-tooth driver gear turns a 45-tooth driven gear. The driver turns 21 times. How many times does the driven gear turn?
  36. 36.⚙️ A 10-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  37. 37.⚙️ A 20-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  38. 38.⚙️ A 12-tooth gear drives a 36-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  39. 39.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  40. 40.⚙️ A motor makes 120 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. 6
  2. 20
  3. driver teeth
  4. 2
  5. 5
  6. 100
  7. 4
  8. 45
  9. 4
  10. 5
  11. 7
  12. 70
  13. 15
  14. 5
  15. 24
  16. 6
  17. 16
  18. 3 times slower
  19. 40
  20. 2
  21. 15
  22. 50
  23. 90
  24. big (slow and strong)
  25. 100
  26. 4
  27. 24
  28. 18
  29. 10
  30. 30
  31. 20
  32. 25
  33. 20
  34. 6
  35. 7
  36. 40
  37. 80
  38. 3
  39. 6
  40. 40

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