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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 279 · 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.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  2. 2.What is the smallest whole number by which 675 must be divided to get a perfect cube?
  3. 3.What is the smallest whole number by which 16 must be multiplied to get a perfect cube?
  4. 4.What is 6³? =
  5. 5.What is 12³? =
  6. 6.A cube has a volume of 5832 cubic cm. How long is each edge (in cm)?
  7. 7.What is the smallest whole number by which 1125 must be multiplied to get a perfect cube?
  8. 8.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  9. 9.What is 11³? =
  10. 10.What is ∛8? =
  11. 11.Which of these is a perfect cube? (a) 1728 (b) 1757 (c) 2103
  12. 12.What is 18³? =
  13. 13.Which of these is a perfect cube? (a) 2744 (b) 2899 (c) 2917
  14. 14.A cube has a volume of 64 cubic cm. How long is each edge (in cm)?
  15. 15.What is 14³? =
  16. 16.A big cube of edge 8 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  17. 17.What is ∛9261? =
  18. 18.Which of these is a perfect cube? (a) 1022 (b) 1200 (c) 1000
  19. 19.What is the smallest whole number by which 256 must be multiplied to get a perfect cube?
  20. 20.What is ∛512? =
  21. 21.A big cube of edge 18 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  22. 22.What is the smallest whole number by which 5 must be multiplied to get a perfect cube?
  23. 23.A cube has a volume of 512 cubic cm. How long is each edge (in cm)?
  24. 24.Which of these is a perfect cube? (a) 1445 (b) 1331 (c) 1535
  25. 25.What is 10³? =
  26. 26.Which of these is a perfect cube? (a) 343 (b) 352 (c) 408
  27. 27.Which of these is a perfect cube? (a) 512 (b) 565 (c) 513
  28. 28.What is the smallest whole number by which 72 must be divided to get a perfect cube?
  29. 29.A cube has a volume of 1728 cubic cm. How long is each edge (in cm)?
  30. 30.What is ∛343? =
  31. 31.What is 13³? =
  32. 32.What is ∛6859? =
  33. 33.A cube has a volume of 6859 cubic cm. How long is each edge (in cm)?
  34. 34.Which of these is a perfect cube? (a) 125 (b) 154 (c) 139
  35. 35.What is ∛1728? =
  36. 36.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  37. 37.What is the smallest whole number by which 576 must be divided to get a perfect cube?
  38. 38.What is 9³? =
  39. 39.What is ∛1000? =
  40. 40.What is 8³? =

Answer key

  1. 216
  2. 25
  3. 4
  4. 216
  5. 1728
  6. 18
  7. 3
  8. 5
  9. 1331
  10. 2
  11. 1728
  12. 5832
  13. 2744
  14. 4
  15. 2744
  16. 64
  17. 21
  18. 1000
  19. 2
  20. 8
  21. 216
  22. 25
  23. 8
  24. 1331
  25. 1000
  26. 343
  27. 512
  28. 9
  29. 12
  30. 7
  31. 2197
  32. 19
  33. 19
  34. 125
  35. 12
  36. 8
  37. 9
  38. 729
  39. 10
  40. 512

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