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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 90 · 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 60-tooth driver gear turns a 15-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  2. 2.⚙️ A 50-tooth driver gear turns a 10-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  3. 3.⚙️ A 10-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  4. 4.⚙️ A 30-tooth driver gear turns a 15-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  5. 5.⚙️ A 12-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  6. 6.⚙️ A 60-tooth driver gear turns a 15-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  7. 7.⚙️ A 100-tooth driver gear turns a 20-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  8. 8.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  9. 9.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  10. 10.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driver turns 21 times. How many times does the driven gear turn?
  11. 11.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) small (fast, weak) (b) never important (c) big (slow and strong) (d) zero
  12. 12.🔢 Gear ratio = driven teeth ÷ … (a) motor volts (b) wheel size (c) number of gears (d) driver teeth
  13. 13.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 50 times. How many times does the driven gear turn?
  14. 14.🔢 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
  15. 15.⚙️ A motor makes 60 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?
  16. 16.⚙️ A motor makes 30 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?
  17. 17.⚙️ A 10-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  18. 18.⚙️ A motor makes 150 turns a minute with a 12-tooth gear on it. That gear drives a 60-tooth gear. How many turns a minute does the 60-tooth gear make?
  19. 19.⚙️ A 12-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  20. 20.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  21. 21.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  22. 22.⚙️ A 20-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  23. 23.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  24. 24.⚙️ A 12-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  25. 25.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  26. 26.⚙️ An 8-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  27. 27.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  28. 28.⚙️ A 24-tooth driver gear turns a 12-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  29. 29.⚙️ A 15-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  30. 30.⚙️ A motor makes 210 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?
  31. 31.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  32. 32.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  33. 33.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  34. 34.⚙️ A 40-tooth driver gear turns a 10-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  35. 35.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  36. 36.⚙️ A 20-tooth gear drives a 100-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  37. 37.⚙️ An 8-tooth gear drives a 16-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  38. 38.⚙️ A 20-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  39. 39.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  40. 40.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?

Answer key

  1. 20
  2. 45
  3. 30
  4. 16
  5. 20
  6. 40
  7. 45
  8. 10
  9. 4
  10. 7
  11. big (slow and strong)
  12. driver teeth
  13. 10
  14. 3 times slower
  15. 30
  16. 10
  17. 20
  18. 30
  19. 2
  20. 3
  21. 3
  22. 60
  23. 5
  24. 36
  25. 24
  26. 16
  27. 6
  28. 14
  29. 75
  30. 70
  31. 15
  32. 45
  33. 4
  34. 16
  35. 4
  36. 5
  37. 2
  38. 2
  39. 4
  40. 5

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