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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 254 · 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 gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  2. 2.⚙️ An 8-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  3. 3.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  4. 4.⚙️ A 20-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  5. 5.⚙️ A motor makes 360 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?
  6. 6.⚙️ An 8-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  7. 7.⚙️ A motor makes 100 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?
  8. 8.🔢 Gear ratio = driven teeth ÷ … (a) motor volts (b) driver teeth (c) number of gears (d) wheel size
  9. 9.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) big (slow and strong) (b) zero (c) never important (d) small (fast, weak)
  10. 10.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  11. 11.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times louder (b) 3 times slower (c) 3 times faster (d) 3 times bigger
  12. 12.⚙️ A 12-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  13. 13.⚙️ A 60-tooth driver gear turns a 20-tooth driven gear. The driver turns 7 times. How many times does the driven gear 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.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  16. 16.⚙️ A 20-tooth gear drives a 100-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  17. 17.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  18. 18.⚙️ A 24-tooth driver gear turns a 12-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  19. 19.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  20. 20.⚙️ A 12-tooth gear drives a 48-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  21. 21.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  22. 22.⚙️ A 12-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  23. 23.⚙️ A motor makes 60 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?
  24. 24.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 12 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.⚙️ An 8-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  27. 27.⚙️ A motor makes 60 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?
  28. 28.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driver turns 35 times. How many times does the driven gear turn?
  29. 29.⚙️ A 20-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  30. 30.⚙️ A 36-tooth driver gear turns a 12-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  31. 31.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  32. 32.⚙️ An 8-tooth gear drives a 32-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  33. 33.⚙️ A 12-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  34. 34.⚙️ A 20-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  35. 35.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  36. 36.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  37. 37.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driver turns 21 times. How many times does the driven gear turn?
  38. 38.⚙️ A 24-tooth driver gear turns a 12-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  39. 39.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 25 times. How many times does the driven gear turn?
  40. 40.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 14 times. How many times does the driven gear turn?

Answer key

  1. 4
  2. 40
  3. 10
  4. 80
  5. 90
  6. 3
  7. 20
  8. driver teeth
  9. big (slow and strong)
  10. 25
  11. 3 times slower
  12. 48
  13. 21
  14. 24
  15. 4
  16. 5
  17. 30
  18. 12
  19. 15
  20. 4
  21. 5
  22. 2
  23. 30
  24. 6
  25. 2
  26. 16
  27. 30
  28. 7
  29. 100
  30. 9
  31. 5
  32. 4
  33. 15
  34. 60
  35. 16
  36. 6
  37. 7
  38. 16
  39. 5
  40. 7

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