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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 145 · 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 12-tooth gear drives a 36-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  2. 2.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times bigger (b) 3 times slower (c) 3 times faster (d) 3 times louder
  3. 3.⚙️ An 8-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  4. 4.⚙️ A motor makes 450 turns a minute with a 12-tooth gear on it. That gear drives a 60-tooth gear. How many turns a minute does the 60-tooth gear make?
  5. 5.⚙️ A 60-tooth driver gear turns a 20-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  6. 6.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  7. 7.⚙️ A 15-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  8. 8.⚙️ A motor makes 240 turns a minute with a 15-tooth gear on it. That gear drives a 30-tooth gear. How many turns a minute does the 30-tooth gear make?
  9. 9.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  10. 10.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  11. 11.⚙️ 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?
  12. 12.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driver turns 50 times. How many times does the driven gear turn?
  13. 13.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) small (fast, weak) (b) zero (c) never important (d) big (slow and strong)
  14. 14.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  15. 15.⚙️ A motor makes 240 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?
  16. 16.⚙️ A 40-tooth driver gear turns a 20-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  17. 17.⚙️ A motor makes 280 turns a minute with a 20-tooth gear on it. That gear drives an 80-tooth gear. How many turns a minute does the 80-tooth gear make?
  18. 18.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  19. 19.⚙️ A 20-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  20. 20.⚙️ A motor makes 120 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?
  21. 21.⚙️ A motor makes 150 turns a minute with a 12-tooth gear on it. That gear drives a 60-tooth gear. How many turns a minute does the 60-tooth gear make?
  22. 22.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driver turns 15 times. How many times does the driven gear turn?
  23. 23.⚙️ A 12-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  24. 24.⚙️ A 36-tooth driver gear turns a 12-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  25. 25.⚙️ A 75-tooth driver gear turns a 15-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  26. 26.⚙️ A 12-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  27. 27.⚙️ A 20-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  28. 28.🔢 Gear ratio = driven teeth ÷ … (a) driver teeth (b) wheel size (c) motor volts (d) number of gears
  29. 29.⚙️ A 15-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  30. 30.⚙️ An 8-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  31. 31.⚙️ A 32-tooth driver gear turns an 8-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  32. 32.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  33. 33.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driver turns 50 times. How many times does the driven gear turn?
  34. 34.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driver turns 24 times. How many times does the driven gear turn?
  35. 35.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  36. 36.⚙️ A motor makes 140 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?
  37. 37.⚙️ A 40-tooth driver gear turns an 8-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  38. 38.⚙️ A 100-tooth driver gear turns a 20-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  39. 39.⚙️ A motor makes 160 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?
  40. 40.⚙️ A 15-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?

Answer key

  1. 3
  2. 3 times slower
  3. 3
  4. 90
  5. 15
  6. 2
  7. 2
  8. 120
  9. 40
  10. 5
  11. 40
  12. 10
  13. big (slow and strong)
  14. 20
  15. 60
  16. 4
  17. 70
  18. 20
  19. 80
  20. 60
  21. 30
  22. 5
  23. 2
  24. 15
  25. 20
  26. 36
  27. 100
  28. driver teeth
  29. 30
  30. 24
  31. 20
  32. 6
  33. 10
  34. 6
  35. 6
  36. 70
  37. 30
  38. 35
  39. 40
  40. 4

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