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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 83 · 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 14³? =
  2. 2.What is the smallest whole number by which 1944 must be divided to get a perfect cube?
  3. 3.What is the smallest whole number by which 1080 must be divided to get a perfect cube?
  4. 4.What is 13³? =
  5. 5.What is 17³? =
  6. 6.A cube has a volume of 27 cubic cm. How long is each edge (in cm)?
  7. 7.What is ∛12167? =
  8. 8.What is the smallest whole number by which 875 must be multiplied to get a perfect cube?
  9. 9.Which of these is a perfect cube? (a) 216 (b) 240 (c) 242
  10. 10.What is ∛1728? =
  11. 11.What is the smallest whole number by which 9 must be multiplied to get a perfect cube?
  12. 12.What is ∛4913? =
  13. 13.A cube has a volume of 2197 cubic cm. How long is each edge (in cm)?
  14. 14.What is the smallest whole number by which 25 must be divided to get a perfect cube?
  15. 15.What is ∛3375? =
  16. 16.What is ∛2197? =
  17. 17.A cube has a volume of 1331 cubic cm. How long is each edge (in cm)?
  18. 18.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  19. 19.A cube has a volume of 2744 cubic cm. How long is each edge (in cm)?
  20. 20.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  21. 21.A cube has a volume of 5832 cubic cm. How long is each edge (in cm)?
  22. 22.What is the smallest whole number by which 500 must be multiplied to get a perfect cube?
  23. 23.What is the smallest whole number by which 5400 must be multiplied to get a perfect cube?
  24. 24.What is ∛1000? =
  25. 25.Which of these is a perfect cube? (a) 41 (b) 27 (c) 33
  26. 26.What is the smallest whole number by which 1512 must be multiplied to get a perfect cube?
  27. 27.Which of these is a perfect cube? (a) 857 (b) 729 (c) 761
  28. 28.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
  29. 29.What is the smallest whole number by which 32 must be divided to get a perfect cube?
  30. 30.A big cube of edge 12 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  31. 31.Which of these is a perfect cube? (a) 3375 (b) 3439 (c) 3409
  32. 32.What is the smallest whole number by which 3 must be multiplied to get a perfect cube?
  33. 33.What is 8³? =
  34. 34.What is the smallest whole number by which 256 must be multiplied to get a perfect cube?
  35. 35.What is ∛216? =
  36. 36.What is the smallest whole number by which 24 must be multiplied to get a perfect cube?
  37. 37.What is ∛8? =
  38. 38.Which of these is a perfect cube? (a) 187 (b) 186 (c) 125
  39. 39.What is 18³? =
  40. 40.What is 4³? =

Answer key

  1. 2744
  2. 9
  3. 5
  4. 2197
  5. 4913
  6. 3
  7. 23
  8. 49
  9. 216
  10. 12
  11. 3
  12. 17
  13. 13
  14. 25
  15. 15
  16. 13
  17. 11
  18. 7
  19. 14
  20. 6
  21. 18
  22. 2
  23. 5
  24. 10
  25. 27
  26. 49
  27. 729
  28. 2
  29. 4
  30. 216
  31. 3375
  32. 9
  33. 512
  34. 2
  35. 6
  36. 9
  37. 2
  38. 125
  39. 5832
  40. 64

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