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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 146 · 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.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  2. 2.⚙️ A 15-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  3. 3.⚙️ 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?
  4. 4.⚙️ A 12-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  5. 5.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  6. 6.⚙️ A 20-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  7. 7.⚙️ A 12-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  8. 8.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) small (fast, weak) (b) big (slow and strong) (c) never important (d) zero
  9. 9.🔢 Gear ratio = driven teeth ÷ … (a) number of gears (b) motor volts (c) driver teeth (d) wheel size
  10. 10.⚙️ A motor makes 60 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?
  11. 11.⚙️ A 10-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  12. 12.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  13. 13.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times louder (b) 3 times faster (c) 3 times slower (d) 3 times bigger
  14. 14.⚙️ A motor makes 90 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?
  15. 15.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  16. 16.⚙️ A motor makes 210 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?
  17. 17.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  18. 18.⚙️ An 8-tooth gear drives a 32-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  19. 19.⚙️ A 20-tooth gear drives an 80-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  20. 20.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 24 times. How many times does the driven gear turn?
  21. 21.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  22. 22.⚙️ An 8-tooth gear drives a 16-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  23. 23.⚙️ A motor makes 440 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?
  24. 24.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 14 times. How many times does the driven gear turn?
  25. 25.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driver turns 3 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.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  28. 28.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  29. 29.⚙️ A motor makes 360 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?
  30. 30.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 36 times. How many times does the driven gear turn?
  31. 31.⚙️ A 10-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  32. 32.⚙️ A 10-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  33. 33.⚙️ A motor makes 160 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?
  34. 34.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driver turns 35 times. How many times does the driven gear turn?
  35. 35.⚙️ A 40-tooth driver gear turns an 8-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  36. 36.⚙️ A 12-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  37. 37.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  38. 38.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  39. 39.⚙️ An 8-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  40. 40.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 30 times. How many times does the driven gear turn?

Answer key

  1. 6
  2. 30
  3. 70
  4. 60
  5. 6
  6. 2
  7. 2
  8. big (slow and strong)
  9. driver teeth
  10. 30
  11. 50
  12. 45
  13. 3 times slower
  14. 30
  15. 4
  16. 70
  17. 9
  18. 4
  19. 4
  20. 6
  21. 16
  22. 2
  23. 110
  24. 7
  25. 1
  26. 60
  27. 6
  28. 4
  29. 90
  30. 9
  31. 40
  32. 20
  33. 80
  34. 7
  35. 20
  36. 24
  37. 5
  38. 24
  39. 16
  40. 6

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