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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 42 · 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 12-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  2. 2.⚙️ A motor makes 360 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?
  3. 3.⚙️ A 20-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  4. 4.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  5. 5.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  6. 6.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times slower (b) 3 times louder (c) 3 times faster (d) 3 times bigger
  7. 7.⚙️ A 15-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  8. 8.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  9. 9.⚙️ A motor makes 160 turns a minute with an 8-tooth gear on it. That gear drives a 16-tooth gear. How many turns a minute does the 16-tooth gear make?
  10. 10.⚙️ A 15-tooth gear drives a 45-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  11. 11.⚙️ An 8-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  12. 12.🔢 Gear ratio = driven teeth ÷ … (a) motor volts (b) number of gears (c) wheel size (d) driver teeth
  13. 13.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  14. 14.⚙️ A motor makes 600 turns a minute with a 20-tooth gear on it. That gear drives a 100-tooth gear. How many turns a minute does the 100-tooth gear make?
  15. 15.⚙️ A 48-tooth driver gear turns a 12-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  16. 16.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driver turns 3 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) big (slow and strong) (c) zero (d) never important
  18. 18.⚙️ A 40-tooth driver gear turns a 20-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  19. 19.⚙️ A 100-tooth driver gear turns a 20-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  20. 20.⚙️ An 8-tooth gear drives a 16-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  21. 21.⚙️ A motor makes 90 turns a minute with an 8-tooth gear on it. That gear drives a 24-tooth gear. How many turns a minute does the 24-tooth gear make?
  22. 22.⚙️ A motor makes 80 turns a minute with a 12-tooth gear on it. That gear drives a 48-tooth gear. How many turns a minute does the 48-tooth gear make?
  23. 23.⚙️ A 15-tooth gear drives a 75-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  24. 24.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  25. 25.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  26. 26.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driver turns 50 times. How many times does the driven gear turn?
  27. 27.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  28. 28.⚙️ A 60-tooth driver gear turns a 20-tooth driven gear. The driver turns 6 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 240 turns a minute with a 15-tooth gear on it. That gear drives a 45-tooth gear. How many turns a minute does the 45-tooth gear make?
  31. 31.⚙️ A 10-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  32. 32.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  33. 33.⚙️ A 12-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  34. 34.⚙️ A 10-tooth driver gear must make the driven gear turn 5 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 7 times. How many times did the driver turn?
  36. 36.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  37. 37.⚙️ A 24-tooth driver gear turns a 12-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  38. 38.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  39. 39.⚙️ An 8-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  40. 40.⚙️ A 12-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?

Answer key

  1. 36
  2. 120
  3. 2
  4. 4
  5. 21
  6. 3 times slower
  7. 45
  8. 8
  9. 80
  10. 3
  11. 16
  12. driver teeth
  13. 1
  14. 120
  15. 40
  16. 1
  17. big (slow and strong)
  18. 16
  19. 15
  20. 2
  21. 30
  22. 20
  23. 5
  24. 10
  25. 6
  26. 10
  27. 10
  28. 18
  29. 6
  30. 80
  31. 20
  32. 3
  33. 48
  34. 50
  35. 14
  36. 12
  37. 6
  38. 8
  39. 24
  40. 24

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