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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 38 · 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 40-tooth driven gear. The driver turns 15 times. How many times does the driven gear turn?
  2. 2.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driver turns 32 times. How many times does the driven gear turn?
  3. 3.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  4. 4.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driver turns 40 times. How many times does the driven gear turn?
  5. 5.🔢 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
  6. 6.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  7. 7.⚙️ A motor makes 100 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?
  8. 8.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  9. 9.⚙️ A 20-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  10. 10.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 36 times. How many times does the driven gear turn?
  11. 11.⚙️ A 15-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  12. 12.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  13. 13.🔢 Gear ratio = driven teeth ÷ … (a) wheel size (b) motor volts (c) number of gears (d) driver teeth
  14. 14.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  15. 15.⚙️ A 75-tooth driver gear turns a 15-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  16. 16.⚙️ A 32-tooth driver gear turns an 8-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  17. 17.🔢 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)
  18. 18.⚙️ A 12-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  19. 19.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  20. 20.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  21. 21.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  22. 22.⚙️ A 40-tooth driver gear turns a 20-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  23. 23.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  24. 24.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  25. 25.⚙️ A 10-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  26. 26.⚙️ An 8-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  27. 27.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  28. 28.⚙️ A 75-tooth driver gear turns a 15-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  29. 29.⚙️ A 15-tooth gear drives a 75-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  30. 30.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  31. 31.⚙️ A 40-tooth driver gear turns a 10-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  32. 32.⚙️ A 10-tooth gear drives a 50-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  33. 33.⚙️ A 40-tooth driver gear turns an 8-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  34. 34.⚙️ A 20-tooth gear drives a 100-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  35. 35.⚙️ A 60-tooth driver gear turns a 20-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  36. 36.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  37. 37.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  38. 38.⚙️ A 12-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  39. 39.⚙️ A 16-tooth driver gear turns an 8-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  40. 40.⚙️ 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?

Answer key

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

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