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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 81 · 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 15-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  2. 2.⚙️ A 48-tooth driver gear turns a 12-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  3. 3.⚙️ A 30-tooth driver gear turns a 15-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  4. 4.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times bigger (b) 3 times faster (c) 3 times slower (d) 3 times louder
  5. 5.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  6. 6.⚙️ A 12-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  7. 7.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driver turns 30 times. How many times does the driven gear turn?
  8. 8.⚙️ An 8-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  9. 9.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  10. 10.🔢 Gear ratio = driven teeth ÷ … (a) wheel size (b) number of gears (c) motor volts (d) driver teeth
  11. 11.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  12. 12.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  13. 13.⚙️ A 36-tooth driver gear turns a 12-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  14. 14.⚙️ A motor makes 20 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?
  15. 15.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  16. 16.⚙️ A 20-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  17. 17.🔢 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)
  18. 18.⚙️ A motor makes 40 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?
  19. 19.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 30 times. How many times does the driven gear turn?
  20. 20.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  21. 21.⚙️ An 8-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  22. 22.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  23. 23.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  24. 24.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  25. 25.⚙️ A motor makes 240 turns a minute with a 10-tooth gear on it. That gear drives a 20-tooth gear. How many turns a minute does the 20-tooth gear make?
  26. 26.⚙️ A 30-tooth driver gear turns a 10-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  27. 27.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driver turns 30 times. How many times does the driven gear turn?
  28. 28.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  29. 29.⚙️ A motor makes 30 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?
  30. 30.⚙️ A motor makes 80 turns a minute with a 15-tooth gear on it. That gear drives a 60-tooth gear. How many turns a minute does the 60-tooth gear make?
  31. 31.⚙️ A 10-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  32. 32.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driver turns 15 times. How many times does the driven gear turn?
  33. 33.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  34. 34.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  35. 35.⚙️ A motor makes 100 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?
  36. 36.⚙️ A 10-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  37. 37.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driver turns 14 times. How many times does the driven gear turn?
  38. 38.⚙️ A motor makes 60 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?
  39. 39.⚙️ An 80-tooth driver gear turns a 20-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  40. 40.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?

Answer key

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

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