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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 134 · 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 1 time. How many times does the driven gear turn?
  2. 2.⚙️ An 8-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  3. 3.⚙️ An 8-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  4. 4.⚙️ A motor makes 240 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?
  5. 5.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  6. 6.⚙️ A 32-tooth driver gear turns an 8-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  7. 7.⚙️ A motor makes 280 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?
  8. 8.⚙️ A motor makes 360 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?
  9. 9.⚙️ A 30-tooth driver gear turns a 15-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  10. 10.⚙️ A motor makes 120 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?
  11. 11.⚙️ A 15-tooth gear drives a 45-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  12. 12.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times bigger (b) 3 times louder (c) 3 times slower (d) 3 times faster
  13. 13.⚙️ A 20-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  14. 14.⚙️ A 20-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  15. 15.⚙️ A 12-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  16. 16.⚙️ A 15-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  17. 17.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  18. 18.⚙️ A 24-tooth driver gear turns an 8-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  19. 19.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  20. 20.⚙️ A 20-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  21. 21.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driver turns 15 times. How many times does the driven gear turn?
  22. 22.⚙️ A 40-tooth driver gear turns a 10-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  23. 23.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) never important (b) big (slow and strong) (c) small (fast, weak) (d) zero
  24. 24.⚙️ A 12-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  25. 25.⚙️ A 36-tooth driver gear turns a 12-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  26. 26.🔢 Gear ratio = driven teeth ÷ … (a) motor volts (b) number of gears (c) driver teeth (d) wheel size
  27. 27.⚙️ An 8-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  28. 28.⚙️ A 10-tooth gear drives a 20-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  29. 29.⚙️ A motor makes 200 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?
  30. 30.⚙️ A motor makes 240 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?
  31. 31.⚙️ A 10-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  32. 32.⚙️ A 10-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  33. 33.⚙️ An 8-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  34. 34.⚙️ A motor makes 600 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?
  35. 35.⚙️ A 45-tooth driver gear turns a 15-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  36. 36.⚙️ 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?
  37. 37.⚙️ 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?
  38. 38.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  39. 39.⚙️ An 8-tooth gear drives a 16-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  40. 40.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?

Answer key

  1. 4
  2. 24
  3. 16
  4. 80
  5. 15
  6. 8
  7. 70
  8. 120
  9. 16
  10. 60
  11. 3
  12. 3 times slower
  13. 100
  14. 3
  15. 5
  16. 30
  17. 3
  18. 3
  19. 3
  20. 80
  21. 3
  22. 4
  23. big (slow and strong)
  24. 60
  25. 18
  26. driver teeth
  27. 32
  28. 2
  29. 40
  30. 120
  31. 30
  32. 3
  33. 5
  34. 120
  35. 3
  36. 60
  37. 20
  38. 8
  39. 2
  40. 30

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