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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 291 · 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 12-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  2. 2.⚙️ A 12-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  3. 3.🔢 Gear ratio = driven teeth ÷ … (a) motor volts (b) wheel size (c) number of gears (d) driver teeth
  4. 4.⚙️ A 20-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  5. 5.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times louder (b) 3 times bigger (c) 3 times slower (d) 3 times faster
  6. 6.⚙️ A motor makes 240 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?
  7. 7.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  8. 8.⚙️ An 8-tooth gear drives a 32-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  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 16-tooth driver gear turns an 8-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  11. 11.⚙️ A motor makes 200 turns a minute with a 20-tooth gear on it. That gear drives a 100-tooth gear. How many turns a minute does the 100-tooth gear make?
  12. 12.⚙️ A 75-tooth driver gear turns a 15-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  13. 13.⚙️ A 10-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  14. 14.⚙️ A 50-tooth driver gear turns a 10-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  15. 15.⚙️ A motor makes 220 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 10-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  17. 17.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  18. 18.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 24 times. How many times does the driven gear turn?
  19. 19.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  20. 20.⚙️ A motor makes 140 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?
  21. 21.⚙️ A 15-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  22. 22.⚙️ A 15-tooth gear drives a 45-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  23. 23.⚙️ A 75-tooth driver gear turns a 15-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  24. 24.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  25. 25.⚙️ A 12-tooth driver gear turns a 36-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  26. 26.⚙️ A 30-tooth driver gear turns a 15-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  27. 27.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 20 times. How many times does the driven gear turn?
  28. 28.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  29. 29.⚙️ An 8-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  30. 30.🔢 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
  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 turns a 40-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  33. 33.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 15 times. How many times does the driven gear turn?
  34. 34.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driver turns 24 times. How many times does the driven gear turn?
  35. 35.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driver turns 24 times. How many times does the driven gear turn?
  36. 36.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  37. 37.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 16 times. How many times does the driven gear turn?
  38. 38.⚙️ A 20-tooth driver gear turns a 10-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  39. 39.⚙️ A 40-tooth driver gear turns an 8-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  40. 40.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?

Answer key

  1. 60
  2. 2
  3. driver teeth
  4. 40
  5. 3 times slower
  6. 80
  7. 1
  8. 4
  9. 100
  10. 6
  11. 40
  12. 25
  13. 30
  14. 15
  15. 110
  16. 20
  17. 35
  18. 6
  19. 1
  20. 70
  21. 2
  22. 3
  23. 30
  24. 4
  25. 6
  26. 10
  27. 10
  28. 40
  29. 32
  30. big (slow and strong)
  31. 24
  32. 6
  33. 3
  34. 8
  35. 6
  36. 6
  37. 4
  38. 6
  39. 35
  40. 24

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