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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 13 · 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 15-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  2. 2.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driver turns 15 times. How many times does the driven gear turn?
  3. 3.⚙️ A motor makes 300 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?
  4. 4.⚙️ A 20-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  5. 5.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  6. 6.⚙️ A 12-tooth gear drives a 48-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  7. 7.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driver turns 45 times. How many times does the driven gear turn?
  8. 8.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times faster (b) 3 times bigger (c) 3 times louder (d) 3 times slower
  9. 9.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  10. 10.⚙️ A 20-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  11. 11.🔢 Gear ratio = driven teeth ÷ … (a) number of gears (b) driver teeth (c) wheel size (d) motor volts
  12. 12.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  13. 13.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  14. 14.⚙️ A 12-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  15. 15.⚙️ A 12-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  16. 16.⚙️ An 8-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  17. 17.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) zero (b) small (fast, weak) (c) big (slow and strong) (d) never important
  18. 18.⚙️ A motor makes 120 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?
  19. 19.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  20. 20.⚙️ A 10-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  21. 21.⚙️ A 12-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  22. 22.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  23. 23.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  24. 24.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  25. 25.⚙️ 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?
  26. 26.⚙️ A motor makes 80 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?
  27. 27.⚙️ A 10-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  28. 28.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  29. 29.⚙️ A 24-tooth driver gear turns an 8-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  30. 30.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  31. 31.⚙️ A motor makes 330 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?
  32. 32.⚙️ A 24-tooth driver gear turns an 8-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  33. 33.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  34. 34.⚙️ 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?
  35. 35.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  36. 36.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  37. 37.⚙️ A 20-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  38. 38.⚙️ A motor makes 350 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?
  39. 39.⚙️ A motor makes 50 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?
  40. 40.⚙️ An 80-tooth driver gear turns a 20-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?

Answer key

  1. 10
  2. 3
  3. 60
  4. 100
  5. 3
  6. 4
  7. 9
  8. 3 times slower
  9. 3
  10. 2
  11. driver teeth
  12. 9
  13. 20
  14. 24
  15. 48
  16. 40
  17. big (slow and strong)
  18. 60
  19. 25
  20. 50
  21. 36
  22. 9
  23. 4
  24. 6
  25. 30
  26. 20
  27. 20
  28. 2
  29. 3
  30. 1
  31. 110
  32. 6
  33. 18
  34. 70
  35. 24
  36. 8
  37. 80
  38. 70
  39. 10
  40. 28

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