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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 75 · 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 20-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  2. 2.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times bigger (b) 3 times louder (c) 3 times slower (d) 3 times faster
  3. 3.⚙️ A motor makes 180 turns a minute with a 15-tooth gear on it. That gear drives a 30-tooth gear. How many turns a minute does the 30-tooth gear make?
  4. 4.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  5. 5.⚙️ A 15-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  6. 6.🔢 Gear ratio = driven teeth ÷ … (a) wheel size (b) motor volts (c) number of gears (d) driver teeth
  7. 7.⚙️ A motor makes 160 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?
  8. 8.⚙️ A 20-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  9. 9.⚙️ A motor makes 40 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?
  10. 10.⚙️ A 10-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  11. 11.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  12. 12.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driven gear turns 3 times. How many times did the driver turn?
  13. 13.⚙️ A 15-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  14. 14.⚙️ A 60-tooth driver gear turns a 15-tooth driven gear. The driver turns 5 times. How many times does the driven gear turn?
  15. 15.⚙️ A motor makes 180 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?
  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.⚙️ A motor makes 60 turns a minute with an 8-tooth gear on it. That gear drives a 16-tooth gear. How many turns a minute does the 16-tooth gear make?
  18. 18.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) small (fast, weak) (b) zero (c) never important (d) big (slow and strong)
  19. 19.⚙️ A 30-tooth driver gear turns a 15-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  20. 20.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driver turns 45 times. How many times does the driven gear turn?
  21. 21.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  22. 22.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  23. 23.⚙️ An 8-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  24. 24.⚙️ A 60-tooth driver gear turns a 15-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  25. 25.⚙️ A 15-tooth driver gear turns a 75-tooth driven gear. The driver turns 45 times. How many times does the driven gear turn?
  26. 26.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driver turns 24 times. How many times does the driven gear turn?
  27. 27.⚙️ A 32-tooth driver gear turns an 8-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  28. 28.⚙️ A 15-tooth driver gear turns a 60-tooth driven gear. The driven gear turns 6 times. How many times did the driver turn?
  29. 29.⚙️ A motor makes 20 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?
  30. 30.⚙️ A 20-tooth gear drives an 80-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  31. 31.⚙️ A 10-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  32. 32.⚙️ A 24-tooth driver gear turns a 12-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  33. 33.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  34. 34.⚙️ A 40-tooth driver gear turns a 10-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  35. 35.⚙️ A 15-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  36. 36.⚙️ A 20-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  37. 37.⚙️ A 12-tooth driver gear turns a 48-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  38. 38.⚙️ A 50-tooth driver gear turns a 10-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  39. 39.⚙️ A motor makes 60 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?
  40. 40.⚙️ An 8-tooth driver gear turns a 16-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?

Answer key

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

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