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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 241 · 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 gear drives a 16-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  2. 2.⚙️ A 30-tooth driver gear turns a 10-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  3. 3.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) big (slow and strong) (b) small (fast, weak) (c) never important (d) zero
  4. 4.🔢 Gear ratio = driven teeth ÷ … (a) wheel size (b) number of gears (c) motor volts (d) driver teeth
  5. 5.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  6. 6.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  7. 7.⚙️ A 12-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 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  9. 9.⚙️ A 10-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  10. 10.⚙️ A motor makes 80 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?
  11. 11.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  12. 12.⚙️ A 48-tooth driver gear turns a 12-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  13. 13.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  14. 14.⚙️ An 8-tooth gear drives a 32-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  15. 15.⚙️ A 40-tooth driver gear turns a 20-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  16. 16.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times bigger (b) 3 times faster (c) 3 times louder (d) 3 times slower
  17. 17.⚙️ A 12-tooth gear drives a 48-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  18. 18.⚙️ A 20-tooth gear drives a 100-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  19. 19.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  20. 20.⚙️ A motor makes 100 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?
  21. 21.⚙️ 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?
  22. 22.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driver turns 28 times. How many times does the driven gear turn?
  23. 23.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  24. 24.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  25. 25.⚙️ A motor makes 450 turns a minute with a 10-tooth gear on it. That gear drives a 50-tooth gear. How many turns a minute does the 50-tooth gear make?
  26. 26.⚙️ A 15-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  27. 27.⚙️ A 15-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  28. 28.⚙️ A 15-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  29. 29.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driver turns 32 times. How many times does the driven gear turn?
  30. 30.⚙️ A motor makes 400 turns a minute with a 15-tooth gear on it. That gear drives a 75-tooth gear. How many turns a minute does the 75-tooth gear make?
  31. 31.⚙️ A motor makes 320 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?
  32. 32.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  33. 33.⚙️ A 12-tooth driver gear turns a 60-tooth driven gear. The driver turns 30 times. How many times does the driven gear turn?
  34. 34.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  35. 35.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  36. 36.⚙️ A motor makes 60 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?
  37. 37.⚙️ A 12-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  38. 38.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  39. 39.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driver turns 27 times. How many times does the driven gear turn?
  40. 40.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?

Answer key

  1. 2
  2. 24
  3. big (slow and strong)
  4. driver teeth
  5. 3
  6. 3
  7. 48
  8. 3
  9. 4
  10. 20
  11. 2
  12. 32
  13. 5
  14. 4
  15. 2
  16. 3 times slower
  17. 4
  18. 5
  19. 18
  20. 50
  21. 70
  22. 7
  23. 4
  24. 2
  25. 90
  26. 45
  27. 75
  28. 30
  29. 8
  30. 80
  31. 80
  32. 2
  33. 6
  34. 3
  35. 10
  36. 30
  37. 36
  38. 2
  39. 9
  40. 24

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