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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 384 · 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 6³? =
  2. 2.Which of these is a perfect cube? (a) 2367 (b) 2227 (c) 2197
  3. 3.What is the smallest whole number by which 200 must be divided to get a perfect cube?
  4. 4.What is 9³? =
  5. 5.What is 16³? =
  6. 6.A big cube of edge 5 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  7. 7.What is the smallest whole number by which 864 must be multiplied to get a perfect cube?
  8. 8.What is 13³? =
  9. 9.A cube has a volume of 6859 cubic cm. How long is each edge (in cm)?
  10. 10.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  11. 11.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  12. 12.What is the smallest whole number by which 250 must be divided to get a perfect cube?
  13. 13.A big cube of edge 12 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  14. 14.What is 18³? =
  15. 15.Which of these is a perfect cube? (a) 406 (b) 343 (c) 376
  16. 16.What is 5³? =
  17. 17.What is 20³? =
  18. 18.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
  19. 19.What is ∛729? =
  20. 20.What is the smallest whole number by which 128 must be multiplied to get a perfect cube?
  21. 21.Which of these is a perfect cube? (a) 692 (b) 570 (c) 512
  22. 22.Which of these is a perfect cube? (a) 836 (b) 906 (c) 729
  23. 23.What is 7³? =
  24. 24.Which of these is a perfect cube? (a) 1898 (b) 1829 (c) 1728
  25. 25.Which of these is a perfect cube? (a) 36 (b) 27 (c) 38
  26. 26.A big cube of edge 15 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  27. 27.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  28. 28.What is ∛5832? =
  29. 29.What is ∛125? =
  30. 30.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  31. 31.Which of these is a perfect cube? (a) 65 (b) 64 (c) 88
  32. 32.What is 17³? =
  33. 33.What is 2³? =
  34. 34.What is the smallest whole number by which 81 must be divided to get a perfect cube?
  35. 35.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  36. 36.What is ∛4913? =
  37. 37.What is the smallest whole number by which 72 must be divided to get a perfect cube?
  38. 38.What is the smallest whole number by which 243 must be divided to get a perfect cube?
  39. 39.Which of these is a perfect cube? (a) 1230 (b) 1025 (c) 1000
  40. 40.What is ∛512? =

Answer key

  1. 216
  2. 2197
  3. 25
  4. 729
  5. 4096
  6. 125
  7. 2
  8. 2197
  9. 19
  10. 20
  11. 5
  12. 2
  13. 64
  14. 5832
  15. 343
  16. 125
  17. 8000
  18. 2
  19. 9
  20. 4
  21. 512
  22. 729
  23. 343
  24. 1728
  25. 27
  26. 125
  27. 8
  28. 18
  29. 5
  30. 8
  31. 64
  32. 4913
  33. 8
  34. 3
  35. 8
  36. 17
  37. 9
  38. 9
  39. 1000
  40. 8

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