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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 36 · 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 150 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?
  2. 2.⚙️ A 24-tooth driver gear turns an 8-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  3. 3.🔢 Gear ratio = driven teeth ÷ … (a) wheel size (b) number of gears (c) driver teeth (d) motor volts
  4. 4.⚙️ A 10-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  5. 5.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  6. 6.⚙️ A 15-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  7. 7.⚙️ A 10-tooth gear drives a 20-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  8. 8.⚙️ A motor makes 280 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?
  9. 9.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  10. 10.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times bigger (b) 3 times louder (c) 3 times faster (d) 3 times slower
  11. 11.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) big (slow and strong) (b) zero (c) never important (d) small (fast, weak)
  12. 12.⚙️ An 8-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  13. 13.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  14. 14.⚙️ A 20-tooth gear drives a 100-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  15. 15.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  16. 16.⚙️ A 20-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  17. 17.⚙️ A 48-tooth driver gear turns a 12-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  18. 18.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  19. 19.⚙️ A motor makes 210 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?
  20. 20.⚙️ A 75-tooth driver gear turns a 15-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  21. 21.⚙️ A 12-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  22. 22.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driver turns 36 times. How many times does the driven gear turn?
  23. 23.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  24. 24.⚙️ A 20-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  25. 25.⚙️ A motor makes 280 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?
  26. 26.⚙️ A motor makes 50 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?
  27. 27.⚙️ A 10-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  28. 28.⚙️ A 60-tooth driver gear turns a 15-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  29. 29.⚙️ 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?
  30. 30.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  31. 31.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  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 10-tooth driver gear turns a 20-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  34. 34.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  35. 35.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  36. 36.⚙️ A 15-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  37. 37.⚙️ A 36-tooth driver gear turns a 12-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  38. 38.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  39. 39.⚙️ An 8-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  40. 40.⚙️ An 80-tooth driver gear turns a 20-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?

Answer key

  1. 50
  2. 3
  3. driver teeth
  4. 3
  5. 16
  6. 2
  7. 2
  8. 70
  9. 8
  10. 3 times slower
  11. big (slow and strong)
  12. 32
  13. 12
  14. 5
  15. 5
  16. 60
  17. 20
  18. 6
  19. 70
  20. 10
  21. 60
  22. 9
  23. 20
  24. 2
  25. 70
  26. 10
  27. 4
  28. 16
  29. 50
  30. 14
  31. 4
  32. 24
  33. 14
  34. 8
  35. 3
  36. 75
  37. 3
  38. 1
  39. 5
  40. 4

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