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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 81 · 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 14³? =
  2. 2.What is ∛729? =
  3. 3.What is 18³? =
  4. 4.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  5. 5.A big cube of edge 8 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  6. 6.A cube has a volume of 64 cubic cm. How long is each edge (in cm)?
  7. 7.What is the smallest whole number by which 2 must be multiplied to get a perfect cube?
  8. 8.A big cube of edge 24 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  9. 9.What is the smallest whole number by which 625 must be divided to get a perfect cube?
  10. 10.What is the smallest whole number by which 1512 must be multiplied to get a perfect cube?
  11. 11.What is 4³? =
  12. 12.What is 6³? =
  13. 13.A cube has a volume of 2197 cubic cm. How long is each edge (in cm)?
  14. 14.What is ∛343? =
  15. 15.A big cube of edge 5 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  16. 16.What is 3³? =
  17. 17.What is the smallest whole number by which 256 must be divided to get a perfect cube?
  18. 18.What is 2³? =
  19. 19.A big cube of edge 15 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  20. 20.What is ∛4096? =
  21. 21.Which of these is a perfect cube? (a) 304 (b) 228 (c) 216
  22. 22.A big cube of edge 20 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  23. 23.A cube has a volume of 27 cubic cm. How long is each edge (in cm)?
  24. 24.Which of these is a perfect cube? (a) 3977 (b) 3375 (c) 3427
  25. 25.A big cube of edge 6 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  26. 26.A cube has a volume of 1728 cubic cm. How long is each edge (in cm)?
  27. 27.What is 16³? =
  28. 28.What is ∛1331? =
  29. 29.Which of these is a perfect cube? (a) 1402 (b) 1384 (c) 1331
  30. 30.What is ∛1000? =
  31. 31.What is the smallest whole number by which 24 must be divided to get a perfect cube?
  32. 32.What is ∛12167? =
  33. 33.What is the smallest whole number by which 1080 must be multiplied to get a perfect cube?
  34. 34.What is 15³? =
  35. 35.A cube has a volume of 2744 cubic cm. How long is each edge (in cm)?
  36. 36.What is the smallest whole number by which 5 must be multiplied to get a perfect cube?
  37. 37.What is ∛125? =
  38. 38.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  39. 39.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  40. 40.A big cube of edge 9 cm is cut into small cubes of edge 3 cm. How many small cubes are there?

Answer key

  1. 2744
  2. 9
  3. 5832
  4. 8
  5. 64
  6. 4
  7. 4
  8. 216
  9. 5
  10. 49
  11. 64
  12. 216
  13. 13
  14. 7
  15. 125
  16. 27
  17. 4
  18. 8
  19. 125
  20. 16
  21. 216
  22. 125
  23. 3
  24. 3375
  25. 27
  26. 12
  27. 4096
  28. 11
  29. 1331
  30. 10
  31. 3
  32. 23
  33. 25
  34. 3375
  35. 14
  36. 25
  37. 5
  38. 5
  39. 20
  40. 27

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