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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 2 · 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 gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  2. 2.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times louder (b) 3 times slower (c) 3 times bigger (d) 3 times faster
  3. 3.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  4. 4.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driver turns 21 times. How many times does the driven gear turn?
  5. 5.🔢 Gear ratio = driven teeth ÷ … (a) driver teeth (b) motor volts (c) wheel size (d) number of gears
  6. 6.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  7. 7.⚙️ A 40-tooth driver gear turns a 10-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  8. 8.⚙️ A motor makes 80 turns a minute with a 10-tooth gear on it. That gear drives a 40-tooth gear. How many turns a minute does the 40-tooth gear make?
  9. 9.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  10. 10.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  11. 11.⚙️ A 12-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  12. 12.⚙️ A motor makes 400 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?
  13. 13.⚙️ A 15-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  14. 14.⚙️ A 60-tooth driver gear turns a 12-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  15. 15.⚙️ A motor makes 60 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?
  16. 16.⚙️ A 20-tooth driver gear turns a 10-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  17. 17.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  18. 18.⚙️ A 10-tooth gear drives a 20-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  19. 19.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  20. 20.⚙️ A 12-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  21. 21.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 30 times. How many times does the driven gear turn?
  22. 22.⚙️ A motor makes 210 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?
  23. 23.⚙️ 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?
  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 10-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  26. 26.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  27. 27.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  28. 28.⚙️ A motor makes 320 turns a minute with a 10-tooth gear on it. That gear drives a 40-tooth gear. How many turns a minute does the 40-tooth gear make?
  29. 29.⚙️ A 15-tooth gear drives a 45-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  30. 30.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) big (slow and strong) (b) never important (c) zero (d) small (fast, weak)
  31. 31.⚙️ A 12-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 must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  33. 33.⚙️ A 20-tooth gear drives a 100-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  34. 34.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  35. 35.⚙️ An 8-tooth gear drives a 32-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  36. 36.⚙️ An 8-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  37. 37.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  38. 38.⚙️ An 8-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  39. 39.⚙️ A 10-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  40. 40.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?

Answer key

  1. 3
  2. 3 times slower
  3. 1
  4. 7
  5. driver teeth
  6. 36
  7. 12
  8. 20
  9. 6
  10. 20
  11. 36
  12. 80
  13. 30
  14. 50
  15. 30
  16. 18
  17. 24
  18. 2
  19. 2
  20. 48
  21. 6
  22. 70
  23. 100
  24. 60
  25. 21
  26. 24
  27. 16
  28. 80
  29. 3
  30. big (slow and strong)
  31. 24
  32. 80
  33. 5
  34. 14
  35. 4
  36. 5
  37. 6
  38. 16
  39. 4
  40. 12

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