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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 239 · 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 24-tooth driver gear turns an 8-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  2. 2.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  3. 3.⚙️ A motor makes 400 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?
  4. 4.⚙️ A motor makes 40 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?
  5. 5.🔢 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
  6. 6.⚙️ An 8-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  7. 7.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  8. 8.⚙️ An 8-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  9. 9.⚙️ An 8-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  10. 10.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driver turns 30 times. How many times does the driven gear turn?
  11. 11.⚙️ A 20-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  12. 12.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  13. 13.⚙️ A 32-tooth driver gear turns an 8-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  14. 14.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driver turns 27 times. How many times does the driven gear turn?
  15. 15.🔢 Gear ratio = driven teeth ÷ … (a) wheel size (b) motor volts (c) driver teeth (d) number of gears
  16. 16.⚙️ A motor makes 550 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?
  17. 17.⚙️ A 75-tooth driver gear turns a 15-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  18. 18.⚙️ A 60-tooth driver gear turns a 20-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  19. 19.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  20. 20.⚙️ A motor makes 240 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?
  21. 21.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) big (slow and strong) (b) small (fast, weak) (c) never important (d) zero
  22. 22.⚙️ A motor makes 60 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?
  23. 23.⚙️ 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?
  24. 24.⚙️ A motor makes 200 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?
  25. 25.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  26. 26.⚙️ A 20-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  27. 27.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  28. 28.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driver turns 36 times. How many times does the driven gear turn?
  29. 29.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  30. 30.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  31. 31.⚙️ A 15-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 an 80-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  33. 33.⚙️ A 30-tooth driver gear turns a 10-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  34. 34.⚙️ A 12-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  35. 35.⚙️ A motor makes 250 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?
  36. 36.⚙️ A 12-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  37. 37.⚙️ A 15-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  38. 38.⚙️ A 10-tooth gear drives a 50-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  39. 39.⚙️ A motor makes 180 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?
  40. 40.⚙️ A 10-tooth gear drives a 20-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?

Answer key

  1. 21
  2. 5
  3. 100
  4. 10
  5. 3 times slower
  6. 16
  7. 24
  8. 32
  9. 3
  10. 10
  11. 60
  12. 3
  13. 28
  14. 9
  15. driver teeth
  16. 110
  17. 10
  18. 12
  19. 16
  20. 120
  21. big (slow and strong)
  22. 20
  23. 20
  24. 100
  25. 40
  26. 40
  27. 8
  28. 9
  29. 27
  30. 30
  31. 30
  32. 4
  33. 30
  34. 36
  35. 50
  36. 60
  37. 4
  38. 5
  39. 90
  40. 2

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