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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 580 · 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 ∛27? =
  2. 2.A big cube of edge 10 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  3. 3.What is ∛8? =
  4. 4.What is 15³? =
  5. 5.A cube has a volume of 2197 cubic cm. How long is each edge (in cm)?
  6. 6.What is ∛5832? =
  7. 7.A cube has a volume of 5832 cubic cm. How long is each edge (in cm)?
  8. 8.A cube has a volume of 3375 cubic cm. How long is each edge (in cm)?
  9. 9.A big cube of edge 18 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  10. 10.What is ∛343? =
  11. 11.Which of these is a perfect cube? (a) 512 (b) 641 (c) 590
  12. 12.What is the smallest whole number by which 4 must be divided to get a perfect cube?
  13. 13.What is the smallest whole number by which 40 must be multiplied to get a perfect cube?
  14. 14.Which of these is a perfect cube? (a) 2197 (b) 2372 (c) 2504
  15. 15.Which of these is a perfect cube? (a) 125 (b) 144 (c) 156
  16. 16.What is 14³? =
  17. 17.A cube has a volume of 512 cubic cm. How long is each edge (in cm)?
  18. 18.A cube has a volume of 1728 cubic cm. How long is each edge (in cm)?
  19. 19.Which of these is a perfect cube? (a) 69 (b) 64 (c) 100
  20. 20.A big cube of edge 5 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  21. 21.A big cube of edge 12 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  22. 22.What is ∛2197? =
  23. 23.What is ∛1728? =
  24. 24.What is 10³? =
  25. 25.What is 8³? =
  26. 26.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
  27. 27.What is 2³? =
  28. 28.What is the smallest whole number by which 5 must be divided to get a perfect cube?
  29. 29.What is ∛9261? =
  30. 30.A big cube of edge 24 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  31. 31.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  32. 32.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  33. 33.A big cube of edge 15 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  34. 34.A big cube of edge 20 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  35. 35.What is the smallest whole number by which 875 must be multiplied to get a perfect cube?
  36. 36.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  37. 37.A big cube of edge 9 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  38. 38.What is 5³? =
  39. 39.A big cube of edge 12 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  40. 40.What is the smallest whole number by which 81 must be divided to get a perfect cube?

Answer key

  1. 3
  2. 125
  3. 2
  4. 3375
  5. 13
  6. 18
  7. 18
  8. 15
  9. 216
  10. 7
  11. 512
  12. 4
  13. 25
  14. 2197
  15. 125
  16. 2744
  17. 8
  18. 12
  19. 64
  20. 125
  21. 64
  22. 13
  23. 12
  24. 1000
  25. 512
  26. 2
  27. 8
  28. 5
  29. 21
  30. 216
  31. 8
  32. 6
  33. 125
  34. 125
  35. 49
  36. 216
  37. 27
  38. 125
  39. 27
  40. 3

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