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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 813 · 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 24 must be multiplied to get a perfect cube?
  2. 2.A cube has a volume of 1728 cubic cm. How long is each edge (in cm)?
  3. 3.Which of these is a perfect cube? (a) 31 (b) 32 (c) 27
  4. 4.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  5. 5.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
  6. 6.What is 4³? =
  7. 7.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  8. 8.Which of these is a perfect cube? (a) 64 (b) 73 (c) 83
  9. 9.A big cube of edge 12 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  10. 10.A big cube of edge 24 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  11. 11.What is the smallest whole number by which 576 must be divided to get a perfect cube?
  12. 12.A big cube of edge 4 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  13. 13.What is 17³? =
  14. 14.What is 2³? =
  15. 15.What is the smallest whole number by which 864 must be divided to get a perfect cube?
  16. 16.Which of these is a perfect cube? (a) 3268 (b) 2782 (c) 2744
  17. 17.Which of these is a perfect cube? (a) 183 (b) 125 (c) 173
  18. 18.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  19. 19.What is the smallest whole number by which 1125 must be multiplied to get a perfect cube?
  20. 20.What is ∛9261? =
  21. 21.Which of these is a perfect cube? (a) 2336 (b) 2625 (c) 2197
  22. 22.What is 6³? =
  23. 23.What is ∛12167? =
  24. 24.A cube has a volume of 1000 cubic cm. How long is each edge (in cm)?
  25. 25.A big cube of edge 18 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  26. 26.A cube has a volume of 4913 cubic cm. How long is each edge (in cm)?
  27. 27.What is 14³? =
  28. 28.What is the smallest whole number by which 128 must be multiplied to get a perfect cube?
  29. 29.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  30. 30.What is the smallest whole number by which 54 must be multiplied to get a perfect cube?
  31. 31.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  32. 32.What is 12³? =
  33. 33.What is ∛5832? =
  34. 34.What is ∛1000? =
  35. 35.What is the smallest whole number by which 1600 must be multiplied to get a perfect cube?
  36. 36.A cube has a volume of 64 cubic cm. How long is each edge (in cm)?
  37. 37.What is ∛8? =
  38. 38.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  39. 39.What is the smallest whole number by which 128 must be divided to get a perfect cube?
  40. 40.What is the smallest whole number by which 5400 must be divided to get a perfect cube?

Answer key

  1. 9
  2. 12
  3. 27
  4. 6
  5. 2
  6. 64
  7. 8
  8. 64
  9. 64
  10. 216
  11. 9
  12. 64
  13. 4913
  14. 8
  15. 4
  16. 2744
  17. 125
  18. 8
  19. 3
  20. 21
  21. 2197
  22. 216
  23. 23
  24. 10
  25. 216
  26. 17
  27. 2744
  28. 4
  29. 7
  30. 4
  31. 8
  32. 1728
  33. 18
  34. 10
  35. 5
  36. 4
  37. 2
  38. 20
  39. 2
  40. 25

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