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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 53 · 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 32-tooth driver gear turns an 8-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  2. 2.⚙️ A motor makes 240 turns a minute with a 10-tooth gear on it. That gear drives a 30-tooth gear. How many turns a minute does the 30-tooth gear make?
  3. 3.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  4. 4.⚙️ A motor makes 160 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?
  5. 5.🔢 Gear ratio = driven teeth ÷ … (a) number of gears (b) wheel size (c) motor volts (d) driver teeth
  6. 6.⚙️ A 15-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  7. 7.⚙️ A 12-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  8. 8.⚙️ A 12-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  9. 9.⚙️ A 20-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  10. 10.⚙️ A 45-tooth driver gear turns a 15-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  11. 11.⚙️ A motor makes 100 turns a minute with an 8-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 40-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  13. 13.⚙️ A 10-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  14. 14.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  15. 15.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times bigger (b) 3 times louder (c) 3 times slower (d) 3 times faster
  16. 16.⚙️ A 12-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  17. 17.⚙️ 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?
  18. 18.⚙️ A motor makes 400 turns a minute with an 8-tooth gear on it. That gear drives a 40-tooth gear. How many turns a minute does the 40-tooth gear make?
  19. 19.⚙️ A motor makes 60 turns a minute with a 10-tooth gear on it. That gear drives a 30-tooth gear. How many turns a minute does the 30-tooth gear make?
  20. 20.⚙️ A 24-tooth driver gear turns a 12-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  21. 21.⚙️ An 8-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  22. 22.⚙️ 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?
  23. 23.⚙️ An 8-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  24. 24.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) big (slow and strong) (b) zero (c) small (fast, weak) (d) never important
  25. 25.⚙️ A 10-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  26. 26.⚙️ A 12-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  27. 27.⚙️ A 24-tooth driver gear turns an 8-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  28. 28.⚙️ A 50-tooth driver gear turns a 10-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  29. 29.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 24 times. How many times does the driven gear turn?
  30. 30.⚙️ 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?
  31. 31.⚙️ A 20-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  32. 32.⚙️ A 40-tooth driver gear turns a 20-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  33. 33.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  34. 34.⚙️ A 16-tooth driver gear turns an 8-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  35. 35.⚙️ A 15-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  36. 36.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  37. 37.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  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.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  40. 40.⚙️ A 15-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?

Answer key

  1. 12
  2. 80
  3. 3
  4. 80
  5. driver teeth
  6. 60
  7. 5
  8. 2
  9. 3
  10. 9
  11. 20
  12. 4
  13. 50
  14. 6
  15. 3 times slower
  16. 35
  17. 70
  18. 80
  19. 20
  20. 6
  21. 32
  22. 70
  23. 16
  24. big (slow and strong)
  25. 3
  26. 24
  27. 18
  28. 45
  29. 6
  30. 10
  31. 60
  32. 4
  33. 36
  34. 2
  35. 2
  36. 10
  37. 45
  38. 2
  39. 32
  40. 75

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