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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 225 · 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 16-tooth driver gear turns an 8-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  2. 2.⚙️ A motor makes 180 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?
  3. 3.⚙️ A 12-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  4. 4.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times faster (b) 3 times louder (c) 3 times bigger (d) 3 times slower
  5. 5.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  6. 6.⚙️ A motor makes 20 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?
  7. 7.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  8. 8.⚙️ 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?
  9. 9.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) small (fast, weak) (b) never important (c) zero (d) big (slow and strong)
  10. 10.⚙️ A 20-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  11. 11.⚙️ A motor makes 210 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?
  12. 12.⚙️ A 30-tooth driver gear turns a 10-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  13. 13.⚙️ A 12-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  14. 14.⚙️ 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?
  15. 15.⚙️ An 8-tooth gear drives a 32-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  16. 16.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  17. 17.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  18. 18.🔢 Gear ratio = driven teeth ÷ … (a) driver teeth (b) motor volts (c) number of gears (d) wheel size
  19. 19.⚙️ A 100-tooth driver gear turns a 20-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  20. 20.⚙️ A 20-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  21. 21.⚙️ An 8-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  22. 22.⚙️ A 12-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  23. 23.⚙️ A motor makes 480 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?
  24. 24.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  25. 25.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  26. 26.⚙️ A 32-tooth driver gear turns an 8-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  27. 27.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  28. 28.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  29. 29.⚙️ A 45-tooth driver gear turns a 15-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  30. 30.⚙️ A 10-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  31. 31.⚙️ A 20-tooth driver gear turns a 10-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  32. 32.⚙️ A 10-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  33. 33.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driver turns 15 times. How many times does the driven gear turn?
  34. 34.⚙️ A 60-tooth driver gear turns a 20-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  35. 35.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  36. 36.⚙️ A motor makes 280 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?
  37. 37.⚙️ A motor makes 220 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?
  38. 38.⚙️ A 15-tooth gear drives a 75-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  39. 39.⚙️ A 12-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  40. 40.⚙️ A motor makes 120 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?

Answer key

  1. 6
  2. 90
  3. 5
  4. 3 times slower
  5. 15
  6. 10
  7. 4
  8. 60
  9. big (slow and strong)
  10. 100
  11. 70
  12. 12
  13. 60
  14. 20
  15. 4
  16. 35
  17. 20
  18. driver teeth
  19. 10
  20. 40
  21. 32
  22. 24
  23. 120
  24. 5
  25. 27
  26. 24
  27. 12
  28. 3
  29. 18
  30. 30
  31. 4
  32. 4
  33. 3
  34. 6
  35. 6
  36. 70
  37. 110
  38. 5
  39. 25
  40. 30

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