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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 115 · 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 20-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  2. 2.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  3. 3.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  4. 4.⚙️ A 24-tooth driver gear turns an 8-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  5. 5.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  6. 6.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driver turns 24 times. How many times does the driven gear turn?
  7. 7.⚙️ A 20-tooth gear drives an 80-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  8. 8.⚙️ A 60-tooth driver gear turns a 12-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  9. 9.⚙️ A 12-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  10. 10.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driver turns 28 times. How many times does the driven gear turn?
  11. 11.⚙️ A 10-tooth gear drives a 20-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  12. 12.⚙️ A 45-tooth driver gear turns a 15-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  13. 13.⚙️ A 20-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  14. 14.⚙️ A motor makes 300 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?
  15. 15.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  16. 16.⚙️ A motor makes 180 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?
  17. 17.⚙️ A 50-tooth driver gear turns a 10-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  18. 18.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  19. 19.🔢 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)
  20. 20.⚙️ A 16-tooth driver gear turns an 8-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  21. 21.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  22. 22.⚙️ A motor makes 30 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.🔢 Gear ratio = driven teeth ÷ … (a) motor volts (b) wheel size (c) number of gears (d) driver teeth
  24. 24.⚙️ A 32-tooth driver gear turns an 8-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  25. 25.⚙️ A 20-tooth gear drives a 100-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  26. 26.⚙️ An 8-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  27. 27.⚙️ A 20-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  28. 28.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  29. 29.⚙️ A 15-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  30. 30.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  31. 31.⚙️ A motor makes 480 turns a minute with an 8-tooth gear on it. That gear drives a 32-tooth gear. How many turns a minute does the 32-tooth gear make?
  32. 32.⚙️ An 8-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  33. 33.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  34. 34.⚙️ A motor makes 160 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?
  35. 35.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times louder (b) 3 times faster (c) 3 times slower (d) 3 times bigger
  36. 36.⚙️ A motor makes 100 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 12-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  38. 38.⚙️ A 48-tooth driver gear turns a 12-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  39. 39.⚙️ 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?
  40. 40.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?

Answer key

  1. 40
  2. 35
  3. 3
  4. 15
  5. 1
  6. 8
  7. 4
  8. 20
  9. 50
  10. 7
  11. 2
  12. 9
  13. 80
  14. 60
  15. 1
  16. 60
  17. 50
  18. 8
  19. big (slow and strong)
  20. 14
  21. 9
  22. 10
  23. driver teeth
  24. 24
  25. 5
  26. 40
  27. 100
  28. 9
  29. 2
  30. 20
  31. 120
  32. 5
  33. 25
  34. 80
  35. 3 times slower
  36. 50
  37. 48
  38. 8
  39. 30
  40. 4

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