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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 511 · 40 sums
TalentJR

The method (Threes make cubes): Cube: n × n × n. Cube root: the number that, used three times, gives the cube. Units digits: 1→1, 2→8, 3→7, 4→4, 5→5, 6→6, 7→3, 8→2, 9→9, 0→0 — use them to guess cube roots. Make a perfect cube: break into primes; multiply by what completes each group of three (or divide by what is left over). A big cube of edge a cut into small cubes of edge b gives (a ÷ b)³ small cubes.

NameDateTime takenScore ___ / 40
  1. 1.What is ∛512? =
  2. 2.A big cube of edge 20 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  3. 3.What is 7³? =
  4. 4.Which of these is a perfect cube? (a) 449 (b) 408 (c) 343
  5. 5.What is 15³? =
  6. 6.What is 3³? =
  7. 7.What is the smallest whole number by which 1323 must be multiplied to get a perfect cube?
  8. 8.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  9. 9.Which of these is a perfect cube? (a) 41 (b) 31 (c) 27
  10. 10.A big cube of edge 12 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  11. 11.What is the smallest whole number by which 4 must be multiplied to get a perfect cube?
  12. 12.A big cube of edge 5 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  13. 13.What is 6³? =
  14. 14.What is 9³? =
  15. 15.What is ∛6859? =
  16. 16.A big cube of edge 24 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  17. 17.What is the smallest whole number by which 24 must be multiplied to get a perfect cube?
  18. 18.A big cube of edge 6 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  19. 19.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  20. 20.What is ∛3375? =
  21. 21.What is 2³? =
  22. 22.Which of these is a perfect cube? (a) 178 (b) 153 (c) 125
  23. 23.What is ∛216? =
  24. 24.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  25. 25.What is 16³? =
  26. 26.A cube has a volume of 2744 cubic cm. How long is each edge (in cm)?
  27. 27.What is 19³? =
  28. 28.What is the smallest whole number by which 250 must be divided to get a perfect cube?
  29. 29.What is the smallest whole number by which 25 must be divided to get a perfect cube?
  30. 30.What is 8³? =
  31. 31.Which of these is a perfect cube? (a) 3820 (b) 3375 (c) 3589
  32. 32.What is 20³? =
  33. 33.What is the smallest whole number by which 72 must be divided to get a perfect cube?
  34. 34.What is the smallest whole number by which 500 must be multiplied to get a perfect cube?
  35. 35.What is the smallest whole number by which 189 must be divided to get a perfect cube?
  36. 36.What is ∛10648? =
  37. 37.Which of these is a perfect cube? (a) 1331 (b) 1681 (c) 1436
  38. 38.Which of these is a perfect cube? (a) 64 (b) 93 (c) 108
  39. 39.A big cube of edge 15 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  40. 40.What is 17³? =

Answer key

  1. 8
  2. 125
  3. 343
  4. 343
  5. 3375
  6. 27
  7. 7
  8. 8
  9. 27
  10. 216
  11. 2
  12. 125
  13. 216
  14. 729
  15. 19
  16. 216
  17. 9
  18. 8
  19. 6
  20. 15
  21. 8
  22. 125
  23. 6
  24. 8
  25. 4096
  26. 14
  27. 6859
  28. 2
  29. 25
  30. 512
  31. 3375
  32. 8000
  33. 9
  34. 2
  35. 7
  36. 22
  37. 1331
  38. 64
  39. 125
  40. 4913

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