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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 71 · 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.🔢 Gear ratio = driven teeth ÷ … (a) number of gears (b) motor volts (c) wheel size (d) driver teeth
  2. 2.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) zero (b) big (slow and strong) (c) never important (d) small (fast, weak)
  3. 3.⚙️ A 15-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  4. 4.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driven gear turns 9 times. How many times did the driver turn?
  5. 5.⚙️ A 100-tooth driver gear turns a 20-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  6. 6.⚙️ A 12-tooth gear drives a 36-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  7. 7.⚙️ A motor makes 500 turns a minute with an 8-tooth gear on it. That gear drives a 40-tooth gear. How many turns a minute does the 40-tooth gear make?
  8. 8.⚙️ An 8-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  9. 9.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times bigger (b) 3 times faster (c) 3 times louder (d) 3 times slower
  10. 10.⚙️ An 8-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  11. 11.⚙️ 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?
  12. 12.⚙️ A 20-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  13. 13.⚙️ A 10-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  14. 14.⚙️ A 12-tooth driver gear turns a 60-tooth driven gear. The driver turns 40 times. How many times does the driven gear turn?
  15. 15.⚙️ 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?
  16. 16.⚙️ A 10-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  17. 17.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driver turns 35 times. How many times does the driven gear turn?
  18. 18.⚙️ An 80-tooth driver gear turns a 20-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  19. 19.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 1 time. How many times did the driver turn?
  20. 20.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driver turns 50 times. How many times does the driven gear turn?
  21. 21.⚙️ A 24-tooth driver gear turns a 12-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  22. 22.⚙️ A 20-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  23. 23.⚙️ A 16-tooth driver gear turns an 8-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  24. 24.⚙️ An 8-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  25. 25.⚙️ A 24-tooth driver gear turns an 8-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  26. 26.⚙️ A 60-tooth driver gear turns a 20-tooth driven gear. The driver turns 3 times. How many times does the driven gear turn?
  27. 27.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  28. 28.⚙️ A 24-tooth driver gear turns a 12-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  29. 29.⚙️ A 20-tooth driver gear turns a 60-tooth driven gear. The driver turns 24 times. How many times does the driven gear turn?
  30. 30.⚙️ A motor makes 160 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 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  32. 32.⚙️ An 8-tooth gear drives a 16-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  33. 33.⚙️ A 10-tooth driver gear turns a 20-tooth driven gear. The driven gear turns 7 times. How many times did the driver turn?
  34. 34.⚙️ A 15-tooth gear drives a 75-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  35. 35.⚙️ An 8-tooth driver gear must make the driven gear turn 4 times slower. How many teeth must the driven gear have?
  36. 36.⚙️ A 40-tooth driver gear turns an 8-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
  37. 37.⚙️ A 20-tooth driver gear turns an 80-tooth driven gear. The driver turns 36 times. How many times does the driven gear turn?
  38. 38.⚙️ A 20-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  39. 39.⚙️ A 100-tooth driver gear turns a 20-tooth driven gear. The driver turns 2 times. How many times does the driven gear turn?
  40. 40.⚙️ A 10-tooth driver gear turns a 50-tooth driven gear. The driver turns 35 times. How many times does the driven gear turn?

Answer key

  1. driver teeth
  2. big (slow and strong)
  3. 45
  4. 18
  5. 30
  6. 3
  7. 100
  8. 24
  9. 3 times slower
  10. 40
  11. 120
  12. 40
  13. 40
  14. 8
  15. 10
  16. 4
  17. 7
  18. 32
  19. 4
  20. 10
  21. 6
  22. 60
  23. 4
  24. 35
  25. 3
  26. 9
  27. 1
  28. 14
  29. 8
  30. 40
  31. 3
  32. 2
  33. 14
  34. 5
  35. 32
  36. 50
  37. 9
  38. 3
  39. 10
  40. 7

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