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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 46 · 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 motor makes 480 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?
  2. 2.⚙️ A 10-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  3. 3.⚙️ A 20-tooth driver gear turns a 10-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  4. 4.⚙️ A 10-tooth gear drives a 20-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  5. 5.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times louder (b) 3 times bigger (c) 3 times faster (d) 3 times slower
  6. 6.⚙️ 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?
  7. 7.⚙️ A motor makes 80 turns a minute with a 15-tooth gear on it. That gear drives a 60-tooth gear. How many turns a minute does the 60-tooth gear make?
  8. 8.⚙️ A 100-tooth driver gear turns a 20-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  9. 9.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) zero (b) never important (c) small (fast, weak) (d) big (slow and strong)
  10. 10.⚙️ A 40-tooth driver gear turns a 20-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  11. 11.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driver turns 36 times. How many times does the driven gear turn?
  12. 12.⚙️ A 15-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  13. 13.⚙️ A motor makes 300 turns a minute with a 20-tooth gear on it. That gear drives a 60-tooth gear. How many turns a minute does the 60-tooth gear make?
  14. 14.🔢 Gear ratio = driven teeth ÷ … (a) driver teeth (b) wheel size (c) number of gears (d) motor volts
  15. 15.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  16. 16.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  17. 17.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  18. 18.⚙️ A motor makes 30 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?
  19. 19.⚙️ A 60-tooth driver gear turns a 20-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  20. 20.⚙️ A motor makes 60 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?
  21. 21.⚙️ A 36-tooth driver gear turns a 12-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  22. 22.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driver turns 15 times. How many times does the driven gear turn?
  23. 23.⚙️ A 20-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  24. 24.⚙️ A 12-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  25. 25.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  26. 26.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  27. 27.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  28. 28.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  29. 29.⚙️ A 20-tooth gear drives an 80-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  30. 30.⚙️ A 24-tooth driver gear turns an 8-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  31. 31.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  32. 32.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  33. 33.⚙️ A motor makes 60 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?
  34. 34.⚙️ A 24-tooth driver gear turns an 8-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  35. 35.⚙️ A 20-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  36. 36.⚙️ A motor makes 400 turns a minute with a 15-tooth gear on it. That gear drives a 60-tooth gear. How many turns a minute does the 60-tooth gear make?
  37. 37.⚙️ A 40-tooth driver gear turns a 10-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  38. 38.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  39. 39.⚙️ A motor makes 210 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?
  40. 40.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driver turns 40 times. How many times does the driven gear turn?

Answer key

  1. 120
  2. 20
  3. 8
  4. 2
  5. 3 times slower
  6. 30
  7. 20
  8. 5
  9. big (slow and strong)
  10. 2
  11. 9
  12. 30
  13. 100
  14. driver teeth
  15. 16
  16. 1
  17. 5
  18. 10
  19. 15
  20. 30
  21. 27
  22. 3
  23. 3
  24. 36
  25. 4
  26. 6
  27. 2
  28. 10
  29. 4
  30. 9
  31. 8
  32. 12
  33. 20
  34. 15
  35. 40
  36. 100
  37. 36
  38. 14
  39. 70
  40. 8

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