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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 78 · 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 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?
  2. 2.⚙️ A 30-tooth driver gear turns a 15-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  3. 3.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 50 times. How many times does the driven gear turn?
  4. 4.⚙️ A 15-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  5. 5.⚙️ A 12-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  6. 6.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  7. 7.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) big (slow and strong) (b) never important (c) small (fast, weak) (d) zero
  8. 8.⚙️ A 10-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  9. 9.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  10. 10.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  11. 11.⚙️ An 80-tooth driver gear turns a 20-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  12. 12.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  13. 13.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  14. 14.⚙️ A 60-tooth driver gear turns a 20-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  15. 15.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  16. 16.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  17. 17.⚙️ A 40-tooth driver gear turns a 10-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  18. 18.🔢 Gear ratio = driven teeth ÷ … (a) number of gears (b) wheel size (c) driver teeth (d) motor volts
  19. 19.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times faster (b) 3 times bigger (c) 3 times slower (d) 3 times louder
  20. 20.⚙️ A 12-tooth driver gear turns a 60-tooth driven gear. The driver turns 50 times. How many times does the driven gear turn?
  21. 21.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driver turns 28 times. How many times does the driven gear turn?
  22. 22.⚙️ A 30-tooth driver gear turns a 10-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  23. 23.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  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 40-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  26. 26.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  27. 27.⚙️ A motor makes 120 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?
  28. 28.⚙️ A 12-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  29. 29.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  30. 30.⚙️ A 60-tooth driver gear turns a 12-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  31. 31.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  32. 32.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  33. 33.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  34. 34.⚙️ A 20-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  35. 35.⚙️ A motor makes 210 turns a minute with a 15-tooth gear on it. That gear drives a 45-tooth gear. How many turns a minute does the 45-tooth gear make?
  36. 36.⚙️ A motor makes 300 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?
  37. 37.⚙️ A 40-tooth driver gear turns an 8-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  38. 38.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  39. 39.⚙️ A 20-tooth gear drives an 80-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  40. 40.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?

Answer key

  1. 70
  2. 2
  3. 10
  4. 60
  5. 24
  6. 6
  7. big (slow and strong)
  8. 40
  9. 4
  10. 10
  11. 36
  12. 9
  13. 6
  14. 9
  15. 16
  16. 20
  17. 40
  18. driver teeth
  19. 3 times slower
  20. 10
  21. 7
  22. 18
  23. 20
  24. 60
  25. 3
  26. 2
  27. 30
  28. 48
  29. 9
  30. 15
  31. 45
  32. 21
  33. 45
  34. 60
  35. 70
  36. 100
  37. 35
  38. 4
  39. 4
  40. 4

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