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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 186 · 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 80-tooth driver gear turns a 20-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  2. 2.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  3. 3.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times bigger (b) 3 times faster (c) 3 times slower (d) 3 times louder
  4. 4.⚙️ A 15-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  5. 5.🔢 Gear ratio = driven teeth ÷ … (a) motor volts (b) wheel size (c) driver teeth (d) number of gears
  6. 6.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  7. 7.⚙️ A 40-tooth driver gear turns a 10-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  8. 8.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driver turns 25 times. How many times does the driven gear turn?
  9. 9.⚙️ A motor makes 160 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?
  10. 10.⚙️ A 75-tooth driver gear turns a 15-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  11. 11.⚙️ A 60-tooth driver gear turns a 12-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  12. 12.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  13. 13.⚙️ A motor makes 80 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?
  14. 14.⚙️ A 60-tooth driver gear turns a 15-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  15. 15.⚙️ A 20-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  16. 16.⚙️ A 100-tooth driver gear turns a 20-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  17. 17.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driver turns 25 times. How many times does the driven gear turn?
  18. 18.⚙️ A 20-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  19. 19.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  20. 20.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) never important (b) small (fast, weak) (c) big (slow and strong) (d) zero
  21. 21.⚙️ A 15-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  22. 22.⚙️ A 45-tooth driver gear turns a 15-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  23. 23.⚙️ A 16-tooth driver gear turns an 8-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  24. 24.⚙️ A motor makes 90 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?
  25. 25.⚙️ A 75-tooth driver gear turns a 15-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  26. 26.⚙️ An 8-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  27. 27.⚙️ A 75-tooth driver gear turns a 15-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  28. 28.⚙️ An 8-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  29. 29.⚙️ A 12-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  30. 30.⚙️ A motor makes 550 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 motor makes 120 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?
  32. 32.⚙️ A 16-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 32-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  34. 34.⚙️ A 60-tooth driver gear turns a 20-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  35. 35.⚙️ An 8-tooth gear drives a 32-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  36. 36.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driver turns 21 times. How many times does the driven gear turn?
  37. 37.⚙️ A 12-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  38. 38.⚙️ A motor makes 150 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?
  39. 39.⚙️ An 80-tooth driver gear turns a 20-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  40. 40.⚙️ A 40-tooth driver gear turns an 8-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?

Answer key

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

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