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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 431 · 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 ∛10648? =
  2. 2.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  3. 3.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
  4. 4.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  5. 5.Which of these is a perfect cube? (a) 3927 (b) 3375 (c) 3969
  6. 6.What is the smallest whole number by which 56 must be divided to get a perfect cube?
  7. 7.What is ∛1728? =
  8. 8.What is the smallest whole number by which 1125 must be multiplied to get a perfect cube?
  9. 9.What is the smallest whole number by which 375 must be multiplied to get a perfect cube?
  10. 10.Which of these is a perfect cube? (a) 1233 (b) 1000 (c) 1155
  11. 11.A cube has a volume of 64 cubic cm. How long is each edge (in cm)?
  12. 12.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  13. 13.Which of these is a perfect cube? (a) 1728 (b) 2056 (c) 1745
  14. 14.What is 20³? =
  15. 15.A big cube of edge 6 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  16. 16.Which of these is a perfect cube? (a) 512 (b) 520 (c) 668
  17. 17.Which of these is a perfect cube? (a) 27 (b) 45 (c) 35
  18. 18.What is the smallest whole number by which 32 must be multiplied to get a perfect cube?
  19. 19.What is ∛12167? =
  20. 20.What is 14³? =
  21. 21.What is the smallest whole number by which 7 must be divided to get a perfect cube?
  22. 22.What is 6³? =
  23. 23.What is the smallest whole number by which 200 must be divided to get a perfect cube?
  24. 24.What is 19³? =
  25. 25.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  26. 26.What is the smallest whole number by which 56 must be multiplied to get a perfect cube?
  27. 27.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  28. 28.A cube has a volume of 2744 cubic cm. How long is each edge (in cm)?
  29. 29.What is ∛9261? =
  30. 30.What is ∛5832? =
  31. 31.Which of these is a perfect cube? (a) 64 (b) 104 (c) 86
  32. 32.What is 4³? =
  33. 33.Which of these is a perfect cube? (a) 2854 (b) 2744 (c) 2834
  34. 34.Which of these is a perfect cube? (a) 236 (b) 216 (c) 317
  35. 35.A big cube of edge 4 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  36. 36.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  37. 37.What is 15³? =
  38. 38.What is 7³? =
  39. 39.What is 8³? =
  40. 40.What is the smallest whole number by which 4 must be divided to get a perfect cube?

Answer key

  1. 22
  2. 7
  3. 2
  4. 8
  5. 3375
  6. 7
  7. 12
  8. 3
  9. 9
  10. 1000
  11. 4
  12. 6
  13. 1728
  14. 8000
  15. 8
  16. 512
  17. 27
  18. 2
  19. 23
  20. 2744
  21. 7
  22. 216
  23. 25
  24. 6859
  25. 216
  26. 49
  27. 8
  28. 14
  29. 21
  30. 18
  31. 64
  32. 64
  33. 2744
  34. 216
  35. 64
  36. 27
  37. 3375
  38. 343
  39. 512
  40. 4

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