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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 37 · 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.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  2. 2.⚙️ A motor makes 250 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?
  3. 3.⚙️ A 20-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  4. 4.⚙️ An 8-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  5. 5.🔢 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)
  6. 6.⚙️ A 15-tooth gear drives a 45-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  7. 7.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  8. 8.⚙️ A 15-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  9. 9.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  10. 10.⚙️ A 10-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  11. 11.🔢 Gear ratio = driven teeth ÷ … (a) wheel size (b) motor volts (c) number of gears (d) driver teeth
  12. 12.⚙️ A 12-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  13. 13.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times faster (b) 3 times louder (c) 3 times bigger (d) 3 times slower
  14. 14.⚙️ A motor makes 480 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?
  15. 15.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  16. 16.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  17. 17.⚙️ A 20-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  18. 18.⚙️ A 12-tooth driver gear turns a 60-tooth driven gear. The driver turns 50 times. How many times does the driven gear turn?
  19. 19.⚙️ An 8-tooth gear drives a 24-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  20. 20.⚙️ A 12-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  21. 21.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 14 times. How many times does the driven gear turn?
  22. 22.⚙️ An 80-tooth driver gear turns a 20-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  23. 23.⚙️ A 15-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  24. 24.⚙️ An 8-tooth driver gear turns a 32-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  25. 25.⚙️ A motor makes 500 turns a minute with a 15-tooth gear on it. That gear drives a 75-tooth gear. How many turns a minute does the 75-tooth gear make?
  26. 26.⚙️ A 12-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  27. 27.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  28. 28.⚙️ A motor makes 360 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?
  29. 29.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driver turns 14 times. How many times does the driven gear turn?
  30. 30.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driven gear turns 4 times. How many times did the driver turn?
  31. 31.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  32. 32.⚙️ A 12-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  33. 33.⚙️ A 15-tooth driver gear turns a 30-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  34. 34.⚙️ A 15-tooth driver gear turns a 45-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  35. 35.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driven gear turns 8 times. How many times did the driver turn?
  36. 36.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  37. 37.⚙️ A 10-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  38. 38.⚙️ A 10-tooth driver gear turns a 30-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  39. 39.⚙️ A 75-tooth driver gear turns a 15-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  40. 40.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?

Answer key

  1. 4
  2. 50
  3. 80
  4. 40
  5. big (slow and strong)
  6. 3
  7. 21
  8. 30
  9. 4
  10. 20
  11. driver teeth
  12. 24
  13. 3 times slower
  14. 120
  15. 3
  16. 2
  17. 40
  18. 10
  19. 3
  20. 48
  21. 7
  22. 36
  23. 2
  24. 1
  25. 100
  26. 36
  27. 10
  28. 120
  29. 7
  30. 8
  31. 2
  32. 60
  33. 6
  34. 1
  35. 16
  36. 9
  37. 30
  38. 2
  39. 40
  40. 27

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