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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 33 · 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 40-tooth driver gear turns a 20-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  2. 2.⚙️ A 100-tooth driver gear turns a 20-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  3. 3.⚙️ A 50-tooth driver gear turns a 10-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  4. 4.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  5. 5.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times louder (b) 3 times faster (c) 3 times bigger (d) 3 times slower
  6. 6.⚙️ A 12-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  7. 7.⚙️ A motor makes 450 turns a minute with a 10-tooth gear on it. That gear drives a 50-tooth gear. How many turns a minute does the 50-tooth gear make?
  8. 8.🔢 Gear ratio = driven teeth ÷ … (a) motor volts (b) number of gears (c) driver teeth (d) wheel size
  9. 9.⚙️ A 20-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  10. 10.⚙️ 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?
  11. 11.⚙️ A motor makes 40 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?
  12. 12.⚙️ A 32-tooth driver gear turns an 8-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  13. 13.⚙️ A 12-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  14. 14.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  15. 15.⚙️ A 12-tooth gear drives a 36-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  16. 16.⚙️ A 60-tooth driver gear turns a 15-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  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 450 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 60-tooth driver gear turns a 15-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  20. 20.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  21. 21.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  22. 22.⚙️ A 10-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  23. 23.⚙️ An 8-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  24. 24.⚙️ A 20-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  25. 25.⚙️ An 8-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  26. 26.⚙️ A 15-tooth gear drives a 75-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  27. 27.⚙️ A motor makes 240 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?
  28. 28.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  29. 29.⚙️ A motor makes 60 turns a minute with a 12-tooth gear on it. That gear drives a 24-tooth gear. How many turns a minute does the 24-tooth gear make?
  30. 30.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) zero (b) never important (c) big (slow and strong) (d) small (fast, weak)
  31. 31.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driver turns 14 times. How many times does the driven gear turn?
  32. 32.⚙️ An 8-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  33. 33.⚙️ A motor makes 40 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?
  34. 34.⚙️ A 20-tooth gear drives a 100-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  35. 35.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  36. 36.⚙️ A 20-tooth driver gear must make the driven gear turn 2 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 20 times. How many times does the driven gear turn?
  38. 38.⚙️ A 30-tooth driver gear turns a 15-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  39. 39.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  40. 40.⚙️ A 32-tooth driver gear turns an 8-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?

Answer key

  1. 14
  2. 40
  3. 50
  4. 4
  5. 3 times slower
  6. 24
  7. 90
  8. driver teeth
  9. 100
  10. 70
  11. 10
  12. 8
  13. 5
  14. 1
  15. 3
  16. 24
  17. 20
  18. 90
  19. 4
  20. 4
  21. 5
  22. 50
  23. 5
  24. 80
  25. 16
  26. 5
  27. 60
  28. 20
  29. 30
  30. big (slow and strong)
  31. 7
  32. 32
  33. 10
  34. 5
  35. 3
  36. 40
  37. 10
  38. 18
  39. 30
  40. 4

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