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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 58 · 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 the smallest whole number by which 135 must be divided to get a perfect cube?
  2. 2.What is ∛8? =
  3. 3.What is 17³? =
  4. 4.What is ∛343? =
  5. 5.What is the smallest whole number by which 500 must be divided to get a perfect cube?
  6. 6.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
  7. 7.What is ∛27? =
  8. 8.A cube has a volume of 64 cubic cm. How long is each edge (in cm)?
  9. 9.A big cube of edge 4 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  10. 10.What is 12³? =
  11. 11.What is the smallest whole number by which 16 must be multiplied to get a perfect cube?
  12. 12.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  13. 13.What is 13³? =
  14. 14.Which of these is a perfect cube? (a) 2655 (b) 2197 (c) 2677
  15. 15.Which of these is a perfect cube? (a) 28 (b) 27 (c) 29
  16. 16.What is 8³? =
  17. 17.A cube has a volume of 5832 cubic cm. How long is each edge (in cm)?
  18. 18.What is the smallest whole number by which 1125 must be divided to get a perfect cube?
  19. 19.What is 18³? =
  20. 20.What is 14³? =
  21. 21.Which of these is a perfect cube? (a) 543 (b) 512 (c) 572
  22. 22.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  23. 23.A big cube of edge 6 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  24. 24.A big cube of edge 12 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  25. 25.What is ∛9261? =
  26. 26.What is 16³? =
  27. 27.Which of these is a perfect cube? (a) 65 (b) 75 (c) 64
  28. 28.What is 19³? =
  29. 29.What is the smallest whole number by which 200 must be multiplied to get a perfect cube?
  30. 30.What is ∛4096? =
  31. 31.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  32. 32.A big cube of edge 9 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  33. 33.Which of these is a perfect cube? (a) 3141 (b) 2880 (c) 2744
  34. 34.What is the smallest whole number by which 9 must be multiplied to get a perfect cube?
  35. 35.What is ∛3375? =
  36. 36.A big cube of edge 8 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  37. 37.What is 20³? =
  38. 38.What is ∛1331? =
  39. 39.What is ∛216? =
  40. 40.A cube has a volume of 512 cubic cm. How long is each edge (in cm)?

Answer key

  1. 5
  2. 2
  3. 4913
  4. 7
  5. 4
  6. 2
  7. 3
  8. 4
  9. 64
  10. 1728
  11. 4
  12. 8
  13. 2197
  14. 2197
  15. 27
  16. 512
  17. 18
  18. 9
  19. 5832
  20. 2744
  21. 512
  22. 216
  23. 8
  24. 64
  25. 21
  26. 4096
  27. 64
  28. 6859
  29. 5
  30. 16
  31. 5
  32. 27
  33. 2744
  34. 3
  35. 15
  36. 64
  37. 8000
  38. 11
  39. 6
  40. 8

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