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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 104 · 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 200 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?
  2. 2.⚙️ A 12-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  3. 3.⚙️ A 30-tooth driver gear turns a 10-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  4. 4.⚙️ A 30-tooth driver gear turns a 15-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  5. 5.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  6. 6.⚙️ A motor makes 500 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?
  7. 7.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) small (fast, weak) (b) big (slow and strong) (c) zero (d) never important
  8. 8.🔢 Gear ratio = driven teeth ÷ … (a) wheel size (b) driver teeth (c) motor volts (d) number of gears
  9. 9.⚙️ A 10-tooth gear drives a 20-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  10. 10.⚙️ An 8-tooth gear drives a 32-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  11. 11.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 40 times. How many times does the driven gear turn?
  12. 12.⚙️ A 12-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  13. 13.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  14. 14.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driver turns 25 times. How many times does the driven gear turn?
  15. 15.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  16. 16.⚙️ A 30-tooth driver gear turns a 15-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  17. 17.⚙️ A 60-tooth driver gear turns a 12-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  18. 18.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times louder (b) 3 times bigger (c) 3 times faster (d) 3 times slower
  19. 19.⚙️ A 24-tooth driver gear turns an 8-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  20. 20.⚙️ A 20-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  21. 21.⚙️ A 15-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  22. 22.⚙️ A motor makes 200 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?
  23. 23.⚙️ A 20-tooth gear drives an 80-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  24. 24.⚙️ A 40-tooth driver gear turns a 10-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  25. 25.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  26. 26.⚙️ A 15-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  27. 27.⚙️ An 8-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  28. 28.⚙️ A motor makes 280 turns a minute with an 8-tooth gear on it. That gear drives a 32-tooth gear. How many turns a minute does the 32-tooth gear make?
  29. 29.⚙️ A 60-tooth driver gear turns a 12-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  30. 30.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  31. 31.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 50 times. How many times does the driven gear turn?
  32. 32.⚙️ A motor makes 90 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?
  33. 33.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  34. 34.⚙️ A 40-tooth driver gear turns a 20-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  35. 35.⚙️ A 40-tooth driver gear turns a 20-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  36. 36.⚙️ A 60-tooth driver gear turns a 20-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  37. 37.⚙️ A 10-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  38. 38.⚙️ An 8-tooth gear drives a 16-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  39. 39.⚙️ A 16-tooth driver gear turns an 8-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  40. 40.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driver turns 27 times. How many times does the driven gear turn?

Answer key

  1. 100
  2. 48
  3. 3
  4. 10
  5. 3
  6. 100
  7. big (slow and strong)
  8. driver teeth
  9. 2
  10. 4
  11. 10
  12. 2
  13. 24
  14. 5
  15. 10
  16. 6
  17. 5
  18. 3 times slower
  19. 3
  20. 100
  21. 45
  22. 50
  23. 4
  24. 16
  25. 2
  26. 30
  27. 40
  28. 70
  29. 50
  30. 15
  31. 10
  32. 30
  33. 20
  34. 20
  35. 4
  36. 30
  37. 3
  38. 2
  39. 6
  40. 9

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