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Robotics Worksheet: Gear Ratio for Kids

Robotics lesson 14: Gear ratio sums · Set 125 · 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 motor makes 240 turns a minute with an 8-tooth gear on it. That gear drives a 24-tooth gear. How many turns a minute does the 24-tooth gear make?
  2. 2.⚙️ A motor makes 480 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?
  3. 3.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 2 times. How many times did the driver turn?
  4. 4.⚙️ A motor makes 200 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?
  5. 5.⚙️ A 100-tooth driver gear turns a 20-tooth driven gear. The driver turns 9 times. How many times does the driven gear turn?
  6. 6.⚙️ A 15-tooth gear drives a 75-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  7. 7.⚙️ A 50-tooth driver gear turns a 10-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  8. 8.🔢 Gear ratio = driven teeth ÷ … (a) wheel size (b) driver teeth (c) number of gears (d) motor volts
  9. 9.⚙️ A motor makes 600 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?
  10. 10.🔢 To climb a steep ramp, a robot needs a gear ratio that is … (a) never important (b) zero (c) small (fast, weak) (d) big (slow and strong)
  11. 11.⚙️ A 12-tooth gear drives a 36-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  12. 12.⚙️ A 15-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  13. 13.⚙️ A 20-tooth gear drives a 100-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  14. 14.⚙️ An 8-tooth gear drives a 32-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  15. 15.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driver turns 45 times. How many times does the driven gear turn?
  16. 16.⚙️ A 30-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 gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times slower (b) 3 times louder (c) 3 times faster (d) 3 times bigger
  18. 18.⚙️ A 15-tooth gear drives a 30-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  19. 19.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driven gear turns 10 times. How many times did the driver turn?
  20. 20.⚙️ A 20-tooth driver gear turns a 40-tooth driven gear. The driver turns 12 times. How many times does the driven gear turn?
  21. 21.⚙️ A 75-tooth driver gear turns a 15-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  22. 22.⚙️ A 30-tooth driver gear turns a 10-tooth driven gear. The driver turns 1 time. How many times does the driven gear turn?
  23. 23.⚙️ A 60-tooth driver gear turns a 20-tooth driven gear. The driver turns 4 times. How many times does the driven gear turn?
  24. 24.⚙️ A 20-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  25. 25.⚙️ A 10-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  26. 26.⚙️ A 20-tooth gear drives an 80-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  27. 27.⚙️ A 75-tooth driver gear turns a 15-tooth driven gear. The driver turns 7 times. How many times does the driven gear turn?
  28. 28.⚙️ An 8-tooth driver gear turns a 24-tooth driven gear. The driver turns 18 times. How many times does the driven gear turn?
  29. 29.⚙️ A 12-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?
  30. 30.⚙️ A 40-tooth driver gear turns a 10-tooth driven gear. The driver turns 8 times. How many times does the driven gear turn?
  31. 31.⚙️ A 20-tooth driver gear turns a 100-tooth driven gear. The driver turns 40 times. How many times does the driven gear turn?
  32. 32.⚙️ An 8-tooth driver gear must make the driven gear turn 5 times slower. How many teeth must the driven gear have?
  33. 33.⚙️ A 10-tooth driver gear turns a 40-tooth driven gear. The driven gear turns 5 times. How many times did the driver turn?
  34. 34.⚙️ A 12-tooth gear drives a 60-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  35. 35.⚙️ An 8-tooth driver gear must make the driven gear turn 2 times slower. How many teeth must the driven gear have?
  36. 36.⚙️ A motor makes 600 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?
  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 60-tooth driver gear turns a 15-tooth driven gear. The driver turns 6 times. How many times does the driven gear turn?
  39. 39.⚙️ A 10-tooth gear drives a 40-tooth gear. What is the gear ratio (driven teeth ÷ driver teeth)?
  40. 40.⚙️ A 20-tooth driver gear must make the driven gear turn 3 times slower. How many teeth must the driven gear have?

Answer key

  1. 80
  2. 120
  3. 6
  4. 100
  5. 45
  6. 5
  7. 35
  8. driver teeth
  9. 120
  10. big (slow and strong)
  11. 3
  12. 4
  13. 5
  14. 4
  15. 9
  16. 12
  17. 3 times slower
  18. 2
  19. 30
  20. 6
  21. 40
  22. 3
  23. 12
  24. 100
  25. 20
  26. 4
  27. 35
  28. 6
  29. 36
  30. 32
  31. 8
  32. 40
  33. 20
  34. 5
  35. 16
  36. 120
  37. 4
  38. 24
  39. 4
  40. 60

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